I am a person who has had RNY gastric bypass surgery last summer. I am also on anti-depressants. I have been through the withdrawal you were talking about, only with a different med, and I know about the "brain zaps". I am on a different anti-depressant now that doesn't make me gain any more weight. The damage had been done, however, with regard to the weight gain. Some things I think you might need to know are the following:
1. Something my doctor told me - 95% of people who lose weight will gain it back (this is meaning people who have NOT had the surgery) So dont beat yourself up for not having kept the weight off thus far. It's apparently something that is hard to do.
2. I agree with previous posters who said the lapband is not the way to go. I have read too many stories on this forum about people who have had to have revisions to their bands because of slippage, or whatever, and they end up getting one of the other surgeries anyway. Also, the other two surgeries have better results than the band.
3. I think instead of wondering if the antidepressants will make you gain the weight back, you should consider getting on a different anti-depressant. But to answer that question, I highly doubt you will gain all of the weight back with either the sleeve or gastric bypass. My father in law had gastric bypass and started at 500 pounds. He's lost lots of weight and yes, gained some back, but he's only around 350 now. Better than 500.
4. Regarding hanging skin, it depends on how big you are to start with, and how much you lose, but yes, many people have hanging skin. From what I hear though, it's worth it for all of the benefits you get from losing the weight. I'm not finished losing yet, so I cant really give you any guidance on the hanging skin stuff yet.
5. Regarding sabotaging yourself and gaining the weight back, I have this to say: Counseling, counseling, counseling!!! When you lose the weight, you go through a range of emotions. I never really understood that until it happened to me. What happens is hormones are stored in your fat. When you lose the fat, the hormones come back out. Then you have to either deal with the issues you are having or start a transfer addiction. This is why so many people have problems after surgery- they look for different coping mechanisms like drinking or shopping or whatever (those were my two issues which I'm fixing as we speak). I'm beginning exercising, and I hope this takes care of it. I'm also in counseling to help deal with my issues instead of eating them away.
6. If you read through this forum, you will see that the surgeries are a just good tool. You still have to do the work of trying to fix the reasons for eating. It forces you to cope instead of eating because you can no longer eat to cope.
Hope this makes sense!! Good luck with whatever you decide to do. If you would like to talk to me further, please dont hesitate to PM me. Take it easy!