I know it doesn't make sense that you still have feelings for him. Especially, when someone treats you rotten and isn't there for you...it's like why do I even bother?
Often, I think we are still in love with what was....or what could be. I see it as potential. The thing about potential is that you may never see it come to bloom. Never. You just have to deal with what is in front of you, today, and not see what could be. Make your decisions from that perspective.