get over jealousy

This has been eating away at me for a long time and it will probably be one of the hardest things to do. I’m dating someone who is completely innocent and amazing to me in every way. He is always there for me, and he always tries to understand me but i feel like he is almost paying for the mistakes of my past lovers because of the way they broke my trust (cheating on me, lying to me etc)
I would really just like to relieve myself and more importantly his feeling of a black cloud always around our heads because most of our issues result from the fact that i have a problem trusting him.