Most Helpful Guy
This dude was presumably using you to hide the fact that he's a closeted homosexual. OR he could be bisexual, in which case he's a cheating/lying piece of shit.
So either way -- obviously you can't be in a successful long-term relationship with him, unless you want to have an open relationship in which he can sleep with dudes on the side.
I believe in letting one minor indiscretion slide (or maybe even a couple) for the sake of saving a relationship, but it sounds like he was engaged in prolonged and highly deliberate cheating. It hurts but he's not the one for you.
Cry over some Sam Smith and then start picking up the pieces.
Most Helpful Girl
Don't worry. This period of sadness will end and you will find someone better