How do you stop being someone's friend without them noticing it?

I want to stop being this guy's friend whom I was once romantically involved with without him knowing it. I want to gradually make it so we have no contact whatsoever. First of all I doubt he is my friend and I feel like he is hiding the friendship when he is around others. The only person who knows we are still friends is his two close best friends. Everyone else doesn't know and he is hiding me as a friend. He contacts me and talks to me less and less. I see him once or twice for a few hours every other week. When I decided it is best to cutoff the frienship he finds himself trying to be around me all the time. He always feels that women can't be friends with him ever because of their inability to seperate their feelings from him when it is really the fact that he doesn't treat you as a friend but as exchangeable property. What I mean he says he is your friend but treats you like your crap and then he tries to hit on you and then when you say know and finally give him he turns on you again and so there is this back and forth with him messing with your emotions and feelings. He destroys these friendships not women. I have tried and tried to be a friend to him yet all I get is hurt. I don't care if he doesn't want to be with me but I do care that he is a good friend to me but he isn't. He has me all stressed out were I can barely sleep at night. Got 3 hours of sleep today and I go many days sleepless. That type of friend is not beneficial to a person purposefully playing with a person's mental and emotional capacity. Would you be friends with him if instead of treating you as just a friend he treats you like an ex-lover who scorned him yet you never did anything? If he treated you as someone to pass the time with and hid you from people as if he was embarrased? If he toyed with you one minute saying he wants to be friends and the next minute wanting to be with you and then not? This has been going on for 10 going on 11 months and I am physically, mentally, and emotionally drained.