Break up??

My boyfriend and I are constantly fighting over big and little things. We have arguments where we talk about everything that gets us mad about each other. The last time we had this huge fight was a couple of days ago. After 3 hours of fighting he said he's gonna change. And that he'll be a better person. Mind you, he's been saying that for the past big fights we've had. I told him he keeps saying that and nothing changes. I thought we were over and done with but when I asked he said were still together and he won't ever leave me. I know we're gonna have a huge fight again. He said if we do that we're just gonna break up and move on with our lives because we don't belong together. I felt so scared when he was yelling and arguing because Ive never heard him talk like that. And ever since that day I've been feeling so annoyed by him because he wants to show me a lot of love and affection now but I feel like it's too late for him to start showing that now. He wants to always be with me now because he wants to avoid his friends sometimes. 
Any thoughts about this?