I'm glad you posted this. I felt so many of the same things you are feeling right now ... everything from thinking it was all a cult to the difficulties of fellowship as an introvert. I'm about 9 months in now and I've come to find that the steps they talk about in the program have started to change me as a person. The steps are vital in order to really 'get' AA. I really just leave the rest ...the zealots, cult feeling, etc. doesn't matter to me anymore. There is really something about these steps that have started to give me some peace and content in my life that I never really had with alcohol anyway. So much of my anxiety has gone away since getting sober and now the types of problems I face are 'good' problems to have if that makes any sense. Has your sponsor started the steps with you? That's all he is required to do with you. Everything else is nice, but he is supposed to guide you through the 12 steps which are vital to real recovery in AA. Sitting in meetings is nice, but it's not, as you are aware, going to keep someone sober forever.
As for the fellowship stuff ... that will get easier with time as you become more comfortable and confident about how AA is working in your life. You'll get to a point where you're more than happy to share your experience to a newcomer and tell him how you got to where you are today. Hang in there and don't give up just yet!