I can relate. I too go through these periods. When I think I'm spending too much time alone, and pitying myself because "no one ever invites me," I force myself to invite someone to do something. Like ask someone to go to dinner after the meeting. I did this last Wednesday night, just asked one person I know from the group. There ended up being 5 of us who had dinner that night and everyone was really thankful for the opportunity, we were all going to go home and be lonely! Someone had to start it. I know that's hard for person with social anxiety, sometimes you need to take a baby step out of your comfort zone.
I saw the same girl at an early Saturday morning meeting, and she said "Hey, you wanna get breakfast after the meeting?" And she and I ate breakfast, it was very pleasant. Starting friendships is just like the rest of the program, simple, but not easy. I have very few real, genuine relationships. As an alcoholic, I don't know how. I started drinking at 13, and that's when my emotional developement stopped. Now 8 months sober, I am learning how to do this, something that for a normie requires no effort!!
I know that this reply only covers part of your OP. The part about in your 20s and etc, I don't have much applicable experience. I do know this, as a drunk in my 20s I became entangled in a very unhealthy relationship, that still has reprocussions today (I'm 41)!! You have the opportunity to have a sober life, some people don't take advantage of that opportunity until much later, and the cost is high. Choose to stay sober, and keep working your program. It is worth it!! Your future will thank you!!