Jealousy issues...

I have awful jealousy issues. And I KNOW I act crazy towards my boyfriend a lot but I just cant stop! Like, i know the things I get mad about are ridiculous but it's like I'm dying inside unless I blurt it out. We've nearly been together for a year. Like it's so bad that I get pissed offb that he's friends with 478900007637376 hot girls on Facebook. It pisses me off when I've seen he's liked their pictures. It's like I obsess over stupid stuff. Like one time, he told Me he prefers blondes, thats his "type". I'm not blonde and it just bothered me.. Like why tell me you're arracted to a quality I don't have??? Ugh. I know I'm childish and I'm trying to stop. I just have such low self esteem. I drive myself crazy with jealousy. I just need to face the fact that there's always going to be girls prettier than me and for some reason he chose me.