What does it mean when your boyfriend keeps accusing you of cheating?

my boyfriend of 9 months has a pretty busy schedule, he's in college, so we see each other when we get the chance which is a couple times a month usually. he sometimes cancels plans last minute because of school and lately its been worst. I feel like I'm putting more effort in the relationship because I change my plans to accommodate to his schedule and he asks to see me when he knows I'm busy. last weekend I tried to talk to him to tell him I feel like we are drifting apart but he randomly accused me of cheating on him. this came to me as a surprise I am def not that type of person and I know he is insecure sometimes because of his previous gfs cheating on him. I had no plans of breaking up but he said he knew I was going to break up with him even though I wasn't. then he called the next day saying we should take a break to think about this and says he cares about me and wants to work it out? I'm so confused? any guys know what this means