Walking through that door the first time is probably one of the toughest things about AA, it is a combination of fear of the unknown and fear of losing your crutch, alcohol. Many folks find a great deal of help from AA, and it is a great starting point for your recovery. You can easily find meetings, the people there are super nice, especially to the newcommers, and it can provide a great structure for getting better.
There are other options out there, but AA is by far the most accessable. I'm not a social person either, and it was really hard to walk though that door the first time, but I did gain a lot from the people and the program. Though I don't consider myself a 12step "member", I have gained a great deal of insight into myself and my problems.
I'm sure there will be plenty of folks along soon (if the haven't already arived while I am writing!!) to share their experiences and wisdom. The most important thing is to never give up. Just by being here you will learn a lot about yourself and your addiction. This is a great first step for you. I wish you well on your journey and welcome you to our community. Take care.