What fifleman said is really profound I agree. But that type of behavoir is not just specific to people who are trying to get off drugs. In fact, some of the most secure & confident people I know in this world are "worry warts" like that.
Whether you're on drugs or not doesn't really matter, although withdrawls are obviously going to aggravate things.
Something I have noticed though is that type of behavoir tends to follow people who actually have things to look forward to in life. Take a bum for instance. No home, no job, no friends, no family, no bed, no car, no phone, no roof over his head... very little to nothing to actually worry about. Maybe he gets free food from a shelter and spends most his days truely living in the present, although I still doubt it. I don't think anyone lives 100% in the present. Worrying is a byproduct of evolution imo. If you want to evolve in life and grow, if you want to have things, you're going to spend a lot of time worrying.
Some people however can spend every waking minute they are alive in fear of something. And those people make excellent candidates for opiate/benzo addiction imo. Take that drug... worries go right out the window. No wonder why 1 out of every 4 adults will develop a substance abuse problem in their lifetime. Stop taking that drug and the fears come back 150%. And it may stay like that a while depending on how much you used. But eventually things DO get better. The worrying becomes 147%... then 6 months later 125%... then a year later 108% etc etc. Maybe you never get back to your regular worrying self too. Maybe your new norm becomes 102%. You get the idea. Its not a big deal as we get use to new things fairly quickly (most of us lol).
Anyway I didn't really do much but describe some fundamental realities of the human condition. People worry. No matter how strong or calm a person may appear, no matter how "hardcore" that ex vietnam vet seems, or that person who was raised in a family so wealthy they never have to work a day their entire life... no matter what, people still worry.. and they worry an awful lot. To a certain degree its natural. And if you lived your life 100% in the moment that would be just as abnormal as worrying 100% of the time. Again there goes that word "balance".
So when you do worry consider what you are actually worrying about. Is it a real issue/problem in your life or a figment of your imagination? And for certain people this can be near impossible to differentiate from. They see even the tiniest things in their life as a valid reason to worry.
I found throughout my life one thing that really helps you worry less, is the one thing that causes people to worry the most. Our fears. Nobody likes facing them. Its for that exact reason we wind up wasting our lifes away from stress. Do you fear your parents death? That you won't ever be able to deal with it? Maybe you're not as afraid of your parents dying as you just are of the word "death" itself. Try going to a cancer ward at that hospital where people are hanging on to their life by a thread and talk to them. Ask them questions. Understand that yes death is not a happy thing, but w/out it we might not ever know what happiness was. The sweet things in life simply can NOT be sweet without the bitter. And the paradox is the more bitter something is, the more sweet the few moments of sweet actually become. Like when I got out of prison for the first time ALL the "sweetness" in my life was amplified times 1000 that entire first year. I was higher than I'd ever been on natural life and no drug could have taken me to that sober state of mind. The adversity in my life was exactly what gave me the ability to appreciate the small things, the really really small things. They all a sudden became BIG good things. Same way we may overamplify our fears, I was overamplifying my happiness. But of course when we look back we rarely remember those moments, its so much easier to remember the negative things. Because fear is a trap, happiness is not. Happiness sets us free from our fears, while our fears isolate us from happiness. They are always fighting back and forth like a ying and yang spinning endlessly inside a circle our entire lives.
I still think though you have to make it a goal in life to face your fears. This is something I've done more than once in my life and it made a MASSIVE difference in how I think. Although I still worry today in the past I use to worry about 90% of the time, now I honestly think its more like 40%. I had a huge huge fear of women. So I devoted 4 years of my life to approaching women sober. Going to bars with a bottle of water and starting conversations, learning how to calibrate my social arsenal and seduce people with words. I joined the seduction community and all my fears of women and rejection went right out the window. At one time of my life I was so afraid to date just because of the break up, I was afraid I wouldn't be able to handle it. Now I can see a woman, have strong chemistry with her, a strong reason to wanna be together, but when things end I have a mentality of abundance now. It doesn't phase me at all like it use to. Sometimes now I even try to get rejected on purpose just to see how far I take a situation. If you're not failing you're not trying to get better is the saying. I realize now how many women are actually out there (Thats an outdated/bad word for me actually, I don't really "realize" it like in the past, it use to be an effort where I felt like I had to force myself to think about other women to *realize they were there, now there is a solid understanding or awareness, I just *know how many women actually exist, and moreso I know I have the skills now to talk to one and be comfortable being myself without a hundred thousand bullshit fears paralyzing me in the process). So I go on to the next person and theres no more overexaggerated greiving process for me after breakups. It also took me a lot of back and forth to reach that balance. At another point in my life I was having one night stands with a different partner 2-3 times every week and was starting to objectify women way too much. So I had to let back in some of the fear I had of women. Yet instead of perceiving them as some mysterious force that had the potential to devastate my life, I just started to view them like me, a person with natural fears and anxieties. Am I afraid of myself? Hell no, so why be afraid of them?
Then my fear of public speaking and the panic attacks it would induce. Thats an even looooonger story. But I'll keep it brief and just say I conquered that fear too. Went to a toastmasters convention, went to a dr/psychologist and another doctor to prescribe me inderal. I started off taking baby steps and did it over and over and over. I was nervous as fuck and failed multiple times, even had a bunch of panic attacks in the process and tried killing myself thats how bad it was. Eventually though over a couple of years I kept at it, and now today I have no compulsive fear of public speaking at all. It got to the point where it was the first thing I thought about in the morning, I thought about it all day long EVEN WHEN I had NO SPEECH to give in the near future. I worried about the possiblity of me just needing to ever do it again. What a literal fucking nightmare that shit became at one point. This was one fear the legitimately put me in a psychward and consumed every ounce of my being. Just SPEAKING in public that is lol.
I had to work on that fear for a while but facing the fear in itself becomes addictive. You get off on it. You get off on the fact that "wow, when I put my mind to something I can really do incredible things.... and I wonder what else I could potentially do for myself now".
Thats why I think people who are consumed by worries are people who not only have things to look forward to but are people who are largely stagnant in terms of self evolution or improvement. You are put on this planet to better yourself (at least thats the map society has sold to us since birth), and if you get stuck in a trap of drug addiction although those drugs initially helped you to not worry, they will slowly make you worry even more than when you were sober. Just for the fact that they will inhibit you from facing your fears. Thats really what life is about imo. Give me one fear, I'll face it, conquer it, then give me another fear and I'll do the same thing. The MORE fears I conquer the more I start to believe I'm a stronger person and the have ability to conquer other fears in my life. I really think thats the key to escaping the endless worrying, you really need to work on yourself.
But in this time you need to also be easy on yourself too. Coming off any habit sometimes you gotta set self improvement to the side for a bit and just focus on getting through a certain span of time w/out using. Then when you stabilize somewhat you can titrate yourself back into your normal fears and stresses, and start the process of conquering them. Anyway I talk wayy too fucking much but this is a topic I've always had a lot to say about. Theres also really good books out there like "Feel the fear and do it anyway" by Susan Jeffers, then "Psychocybernetics" by Maxwell Maltz, and "Don't Sweat the Small Stuff" of which I forgot the author. But those 3 books helped me alot in motivating me to chill the fuck out, so maybe they will help you too. Just don't forget though in the end its about putting those books down, getting up and actually enacting a new behavoir. Thats what always counts the most.
g/luck! - Bo