I think he has a lot of issues. The one that leaps out of me is that he is playing the victim here, and blaming you for everything in his life that he doesn't like. Work, overweight and whatever. This of course, is not healthy - he's a grown man, and totally responsible for his own life and choices he makes.

To be abusive to you is a real red flag. To keep breaking up with you is another. It sounds to me that you both may have run your course together. This relationship isn't healthy anymore. Without him getting some help, and sorting through some issues, then I can't see it improving sadly.

My advice? Take some time out - take the decision away from him and make it yourself. Let him do what he needs to do, and if he does it. IF you guys are meant to be, then sometime you may hook up again in the future, but at the moment I think he's just hurting you too much and I think it's time to look after yourself. I know a year long relationship is hard to walk away from, but 4 months is a long time to be unhappy.

Of course, this is just my opinion, and you do not have to listen to a thing!

Take care, and good luck.