Help, don't know what to do.

Me and my boyfriend just broke up. The night it happened he went straight to Facebook and snap chat and started flirting with girls. I know because he told me, & I didn't belive it so he sent me a screenshot of it. I'm so hurt, I love him and still want to be with him. But all he keeps doing is talking down on me and sayin he don't want me that he gonna find a better girl. Then he'll be ok with me for like an hour and say everything's gonna be ok, & I'll try to call him later and he starts acting up again with rejecting my calls and talking shit to me. And again with the flirting on Facebook and snap. I know I need to let go and move on, but it's so hard because I love him and still want to be with him.