8 months ago I moved to a different city, got sober and deleted the phone numbers of every single person I knew besides my parents and my ex girlfriend (the one i still talk to from a while back, and she lives on the other side of the country anyway, along with my parents.)
So I have had to try and make new friends starting basically from scratch. It's been one of the most difficult 8 months of my life. I have only gotten close to one person, and she recently left me and needs an unspecified and possibly indefinite amount of "space" where she doesn't want to talk to me even though she still cares for me, apparently.
So basically back to square one, and I totally feel for you and relate. I read that you quit doing drugs - Have you tried going to any AA/NA meetings? specifically young peoples meetings. Even if you don't need to work the steps or get seriously involved, they can still be a great source of potential friends that don't use drugs. Have you thought about taking some classes at a community college? I saw that you say you finished school, but it can never hurt to take a couple random classes you're interested in and meet some people through them. I just started back in school today so I'll be doing my best to meet people in my classes.
Otherwise, basically the point is that I'm struggling with the same thing but I know there is a light at the end of the tunnel regardless of whether or not I can see it yet, I know it's there. It can be difficult at first but just try and force yourself to be more outgoing and talk to random people. I've been starting to force myself over the last couple weeks, and have made a bunch of new acquaintances that I am hoping will develop into friendships - Time will tell but I know one thing is for sure, If I continue sitting around sorry for myself like I did the first 7 months I was sober then nothing will ever change and I really will die alone. You have to be the change you want to see in your life!