Why don't you stop focusing on him so much? This is how many threads you've made about him? This is how many boundaries you've crossed that got you to this emotional mess in the first place? If you can't just coast on your own convictions that you're better off without him and learn to control your emotions then perhaps you'd do well to go see your doctor and get a referral for a psychological consult.
You've put him on a pedestal, you've framed him as the prize when he already has a lover in his life. Now you're having a hard time accepting that you haven't won him away from her. If you accept that you're better off without him, that you don't need the crumbs he gives you that you allowed yourself to become vulnerable to, then you'll get rid of the residual obsession (yes obsession) that you have for him.
If you won't go get therapy for yourself then at the very least go to your library or your local book store and browse the self-help section for titles on how to stop your focus of this twit and that will help you to get to the stage of indifference to him.
He's not yours to pine over so stop wasting your time and do the work you need to do to get to that blissful stage of indifference. As you've discovered wallowing in your disappointment is doing you no good and he certainly doesn't care that you are. So snap out of it, luv. You're wasting valuable dating time in the current state you're in.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion