Confused in my relationship

Me and my boyfriend have been together for over a year now and have gone through a lot In that time together. Lately we have been arguing a lot because he isn’t taking care of me properly. I have mental health issues that he not only is aware of but that he has taken responsibility to help improve. After I told him how helpful he is, he promised to be better, make me happy, stress free, and selfless/considerate. Lately, he has repeatedly broken those promises. He is sometimes the only stressful thing of my day. I once asked him to come over because I wasn’t feeling good, he said no because it is inconvenient and not worth it. Times like these make me want to dump him and move on. I already daydream about guys that don’t exist in my head to make myself happy. But he helps so much (when he does) and I think that’s why I struggle to let go. I think of the few good times more. I tell myself it’s worth all the hell he puts me through. I tell myself that maybe this time he really means it. I don’t know what to do.