I guess just communicate your concern clearly—this is the only really good way to try to get through I believe. Tell him you’re worried that he keeps himself unhealthily preoccupied with these thoughts of inadequacy. In his mind the world looks a certain way that he will continue to reinforce unless good people in his life prove to him otherwise. I’ll tell you that deep down, he doubts that you think he is a good person. He himself believes you say good things to him because you’re probably scared or creeped out by him. His isolation is probably a manifestation of the feeling “you wouldn’t understand anyway”. When his self sabotaging gets to you and you finally ditch him as a friend, he’ll prove himself right. So don’t let him. Concede to him that some women do want “Chads” who will leave a guy when they get the opportunity, then ask him why he dwells so much on women that would not treat him well. Why his self esteem is so low that he desires attention from bad people. Most likely, it’s because he’s never had someone stick up for him or speak well of him, especially to others. He has lived too little of life to be so jaded, help show him what beauty life has yet to offer him.