All the questions on this fellow have been merged in one place for the whole story.
You tell this fool to get out of your life and stay out until he can get over his issues and stop freaking you out about them. The mistake you make is allowing him to wallow in his own misery, and make you miserable. This is his issue to deal with and you better make him deal with it, by not allowing his insecure immature crap.
You cannot help him, you can only not allow his BS to be your BS!! After rereading this whole thing its obvious he is trying to keep you as a sex partner, but can't marry you, so stop wasting your time being his miserable love toy. You tell him get real, get help, or get gone.