I need some serious help.

Tara
Okay I am always blaming my boyfriend for stuff like let's say we argue over something dumb some how I will manage to work a female into things like I'll just say he was cheating or he's talking to someone else no matter what the argument is I always blame him for messing around behind my back when he says he will never do that to me because of my past relationships where my ex's either left me for another girl or was cheating on me so now I feel like he will leave me for another girl or I feel he is cheating on me I never once had a relationship before that didn't involve cheating or leaving me for another female ....I need help getting me out of this blaming him for cheating and stuff.... when we aren't arguing I believe he doesn't do anything wrong and that he never will but once an argument starts I think 100% different. We have been together for 3 years and 4 months. I really need help this has been going on with me for pretty much our whole relationship and I'm scared I'm going to push him away. I just ask for help. Please... and we are also pregnant with our first and idk I just need help.