How do I fix a relationship when I have gotten jealous too much.

[Mindylove]

So, I have been dating this guy for almost a year and a half. We have broken up a few times for him flirting but we got back together a while ago and we haven't had that problem and everything was going great. Until recently I have been getting so jealous about girls, he is a very good guy so everyone loves him at school which means he has lots of girl friends. And that makes me so mad and jealous. I always get mad and over react about it. People tell me that when he talks to them it looks like flirting, but he swears that he's not flirting and it's being nice and just talking. Because I have gotten jealous too much he says he's sick of it and latley has been feeling differently. I have no clue what to do because I love him and do not want to lose him. What should I do...?