I also had a long period of sobriety - it was only 5 years, but it was good for me. I didn't lose 100 lbs -- that's really impressive! -- but I lost 40.
I think that by not feeling like you fit in, you fit in more than most of us. If that makes any sense. Even the worst setbacks can be recovered. I wish you the best of luck.
Message me sometime if you want and we can talk about how to do it.