You know what you gotta do man....
if smoking weed and drinking make you feel guilty, do not continue to smoke or drink, simple as that.
If you're going to sacrifice your sobriety in order to not be ashamed either....you'll just end up relapsing anyway. Stop putting it off either tell the people at NA/AA or tell SOMEONE. But the guilt from NOT telling them is going to cause you to relapse.
Me personally? I have 0 guilt with smoking some weed every now and then, although I am trying VERY HARD to stop because I no longer like the person I am when Im' high. I've drank prob 3 times too in my 6-9 months off of all other drugs (only things i've done are smoked weed and drank those 3 times). The difference is i don't feel guilty about it. If i DID feel guilty the guilt WOULD cause me to relapse. So either get the guilt off your chest or dont, but you know exactly what it will cost you if you dont.
Textbook addict thinking: "I dont wanna tell them b/c i'll feel ashamed and might lose my housing..." what the fuck do you think will happen if you relapse as a result of said guilt? The same thing that you're worried about, except it will be a billion times worse...
Either way stop drinking and smoking; it obviously does you more harm than good. Soooooooo yeah, you know all this man.
This is actually one of the exact problems i have with AA/NA: its can become a dick sizing competition about CLEAN TIME. and yeah it DOES take balls to stand up at a meeting an confess you've fucked up, because you are 100% right, although theyre not supposed to judge you, those peoples entire lives are based around their "clean time". They definitely have a clique hierarchy of clean time in NA/AA, which I HATE. If you fuck up people CAN ostracize you instead of supporting you. "oh this guy threw away 6 months, what a loser", despite all of their non judgemental preaching. One reason I do not like NA/AA: they are hypocritical in this regard.
But just remember this b/c I found it helped me confess the same exact thing you are about to: who the fuck is someone in a 12 step to be judging you? If someone in a 12 step is judging you they're virtually useless hypocrites. So just take it in stride man & remember theyre in NO position to be judging you fairly, even (and especially) if they do.
Check out LIFERING, see if you have any near you. Secular, non step format. Kinda like NA/AA except I feel much much much superior (because they seek to IMPROVE your life and conditions, not to separate everything into such black and white terms, like 12 steps do). What I like about LIFERING is that they ADMIT that they do not have a magical answer, because there isn't one. Everyone takes a slightly different path to sobriety; unlike 12 steps which do eerything but claim that they are the only solution to a complex (albeit simultaneously simple) problem. Its kind of ironic 12 steppers claim its the ONLY way for an addict to get clean despite the overwhelming amount of evidence saying that a combination of: meetings (12 steps/LIFERING), therapy, and in some cases medication assisted therapies (ie suboxone/methadone) is obviously the best option if you look at it from a purely statistical point of view.
But as we all know, addiction is illogical, meaning statistics dont mean a whole lot. Also why its important to utilize different methods and different manners. If NA makes you feel guilty, get the fuck outta there. This was another problem for me; even though i am working a suboxone program exactly how it should be worked, and have not touched an illicit drug besides marijuana since February. They made me feel like I was wrong because i wasn't doing it their way. And if thats how NA/AA makes you feel? Fuck em.