Trust

My boyfriend and I have been together for about 3 years. Within our relationship, he broke up with me.. Claimed he was tired of the relationship, and was no longer attracted to me..which seemed ironic because i was always dressed nice, i have a curvy body, would always cater to his needs, was always attentive, even his parents adored me, and still did after the break up..We got back together two months later.

I found out that he had slept with 20+ women during this time, was on tinder and OK cupid, being a fuck boy. That did not bother me because we weren't together at the time. Months later, I find out that he was never faithful. He would always send and receive nudes, as well as tell me he'd be out with his friends..when in reality, he'd be out having sex and going on dates with women from these sites. Now, I know for a fact that all that has stopped, but because he wasn't faithful throughout the entire relationship, I can't trust a word he says. He's a compulsive liar, but I love him. Due to certain circumstances, we are also now living together. He gets upset that I can't trust him..but being hurt so many times by the one person that means the world to you..it leaves a mark.

I don't see myself ending the relationship...What can I do to help with the trust issues I now have?