can anyone give me advice?

Ch
I've always been jealous I've tried to igonore it and not to be but I don't want to be like that I know it must suck to have a girlfriend like me. I want to change but it's so hard I just see so much in the other girls he looks at or sees. I just want to be all that and I know I can't . How do I stop being so jealous? And insecure? I'm not terrible looking and my body is okay . I'm a pretty flat human but he loves me .