Any tips on how to overcome jealousy?

Long story short, I love my boyfriend so very much, he's given me no reason to distrust him, and he's open and honest with me as far as I know. However, I dunno, I get super jealous when he uses his phone for too long, stupid I know but I can't seem to help it. He does live with me, and as I said I have no reason to distrust him. I suppose I'm just not 100% able to believe someone could genuinely love me for me, and I realize that's my own problem to work out but that's another story. My main question here is how to overcome the bits of jealousy I feel sometimes. I don't want to feel this way, and if I could get over this I think I'd be much happier.