I can only speak from my own experience, but the ISTP I was seriously involved with was even more messed up sounding than the guy you're currently hog-wrasslin', but regardless of his bad behavior, drugs, shady past that to this day I still have no full knowledge of, I knew how he felt about me. It was an unconscious drive that he couldn't control or cover up. No doubt that freaked him out pretty badly as it did me. Seeing through someone is an experience not to be missed.I'm hoping that he doesn't think that I lead him on or something. I, of course, have no idea what his feelings for me really are. Realistically, though, he is not showing positive signs of being interested.
Because of his problems, our contact became limited (a good thing, no doubt). He was bad off. He wound up in a LTR with a girl that he didn't even seem to like much, but his parents liked, and every time one of our mutual friends mentioned me, it would send him into something of a quiet but visible nervous breakdown, as if he was a doomed man and expected me to come through the door at any moment and ruin everything.
My point is: you should create shockwaves in a man's psyche, be impossible to ignore or keep away from, burn an impression into his brain against his will. You have that power. Everyone does. Napoleon must meet his Waterloo sometime. This guy? Not your Napoleon. Wouldn't it be amazing to be that Thing Which Cannot Be Denied?