Getting over the past...

So I'll give it to him, my boyfriend was pretty honest with me for the most part about how many people he'd slept with and about how many he'd hooked up with. There's just something bothering me about how he was pretty much a fuckboy. He says he would never cheat on me but after hearing he'd been with multiple girls in just a couple days... it's just hard for me after being in a past relationship that I was cheated on in and it was kind of abusive too. Any advice would be greatly appreciated. (Also we are in kind of a rut right now with our sex life and I think this partially has to do with it)
Additional things... he basically had said that if I would have been like he was he probably wouldn't have dated me especially if I had slept with a lot of guys. Said that he wouldn't have been able to take me for a serious relationship girl...