Ripping the Bandaid Off

I did it. I broke up with my fiance. It was so difficult to do and I'd been dragging our relationship out for so long knowing I didn't want to be in it anymore. But I finally got up the courage to do it and all I can do now is worry about him. He's devastated. He keeps blaming himself for everything and apologizing. Its terrible. I try to tell him that its about me and what I want and that he really didn't do anything wrong, but he doesn't hear that. I have so much anxiety today. My stomach is in knots and my muscles are all tense. It would probably be easier and make a lot more sense to him if I told him there's someone else. But I can't do that. The other guy is one of his best friends too and we don't want to ruin that. He's going to need friends to lean on and that would just make it worse. I just can't stop worrying right now. I feel so bad. He just recently admitted to being an alcoholic and this isn't going to make that any easier to deal with. I'm afraid he'll just slip into depression and drink all the time. I really do care about him so much and I want the best for him. He just doesn't seem to know how to do that for himself.