I think you have gone above and beyond for your friend.And you did right to speak to his parents if he is having suicidal thoughts. All we here can do is pray for your friend that he doesn’t do something drastic. I guess sometimes people see others paired up, and wonder why am I not with someone? I am I too picky, too fat, a freak, boring etc.
I know you have tried to help. I once said to my late mother that no body would want me, and she said i don’t give anybody a chance. But often you feel like others don’t or won’t give you a chance, and maybe that’s what he felt.Maybe he came on as too desperate or needy to these ladies.
Is there say a church that he would go to? If you know which one, perhasp you could speak to the pastor, about the situation. Maybe, not saying it will happen, but maybe he will actually talk and listen to the reverend and heed his advice since he doesn’t want to listen to you or family.