I was so scared before my first trip to AA that I literally turned the car around and started driving back home three or four times before I decided to just go do it. I am extremely glad that I did go in and check it out. It has helped save my life.
Just keep telling yourself that you don't have to say anything (you really don't) and that literally every person in the room has been in a situation similar to the one you find yourself in right now. I think you'll find it to be a very welcoming and compassionate group of people.
And if you don't feel comfortable in that group, for any reason, try a different one. Every group takes on its own dynamic and if the first group you go to doesn't inspire you to want to come back, give another group a chance. I've been to 5 and 2 became my regular groups. Keep trying until you find one that's right for you.
Best of luck to you. The program really has worked for millions and it can work for you, too.