I too know the battle of just not being able to accept when a relationship is bad and needs to be ended. His actions are speaking louder than his words unfortunately.

Find yourself a nice group of girlfriends to hang out with and cut him totally out of your life. Block his number off your phone, do NOT contact him. It will take a good few months of not seeing him, or speaking to him before your heart and soul accepts this.
And running back for sex is very hurtful. the bonds between you get renewed every time. As nice as it is, you need to stop doing this

(((HGUS)))