Most Helpful Guy
It's hard to get over a SO other cheating, so don't feel bad there. Once that trust is lost, it's hard to get back. But here's the thing, you're either going to have to forgive him and trust him or you have to leave him, bc you can't go on living the way you are. If you can't forgive him and trust him anymore, then I would say leave, bc you're going to be miserable until you leave and find someone you can trust.
Most Helpful Girl
He cheated, relationship over, whether you want to accept that between you or not. He didn't value it enough not to cheat, you don't respect yourself enough to end it. If you accept that behaviour, which you have, why would he respect you? Since he's already deceived you and cheated, why would you trust him? The two of you should stop play-pretending because it's not going to become a good relationship when it has already been damaged that much by deceit, lies, and disrespect. You can't get trust like that back, he isn't going to be more "faithful" over time, because you already let him get away with cheating. You're just wasting your own time until it inevitably ends.