Should I end this?

I have been with my boyfriend for 5 years, the first 2 years was good, but everything else went downhill. I got more moody, emotionally abusive and stop respecting him. He on the other hand smoke a lot more and take me for granted. We always try to work things out to be a better person, I feel like I would get there and then I’m back to being how I was. He told me how much I broke him as a person and if this end he’s going to kill himself not only because of me but how shitty his life is. I feel like I’m staying to save him, but I keep hurting myself. I enroll him in school, find him a job, let him live rent-free and just surprise him with random gifts from time. I do feel like I’m being used but it was my intent to try to help him out to make his life easy as much as possible. When things go bad, I punch the wall, bang my head and even have a seizure attack. I just never thought it would be like this. I think I put so much time and energy and it’s going like this. I resent him a lot for choosing drugs over me and just not treating me as special as a wanted and it’s overwhelming.