How can I learn to love myself

I'm a real insecure person, and it's ruining my relationship, I keep saying I'll try and that I'll get better but I keep getting into the same loop of insecure jealous and then just being a bad girlfriend I don't want to be like that and I know it's tearing him away from me, he's probably going to break up with me before I get some responses but either way I need this help or I'll be miserable my whole life. Please help;(