I am not familiar with OA. But there is a forum right here at 3FC on it. It can be found in the Chicks in Control forum.
Good luck to you with whatever you decide to go with. I do think the most important thing to do is to find a plan that you can live with forever. Yes, that means making sacrifices at times, learning to make better choices and doing without - but the rewards far outweigh any and all sacrfices. For me, I always said I can't ever lose weight, I have no control. But I've figured out that yes, I always DID have control. I was the indeed the one controlling what went into my mouth. I was the one controlling the fact that I sat on the couch too much. What I didn't have was discipline. The discipline to say no, you just can't do that. It is unacceptable. I couldn't have it both ways. I couldn't eat all that I wanted and be healthy all at the same time. So for me learning discipline was vital.
We all have to find our own way. Don't ever give up. There IS something out there for you. Good luck.