To touch on your particular situation, melancholy65. What stands out to me in your description of this man is that you said he is so sad and depressed. Narcissists, for instance, usually do not exhibit deep depression unless they have received a severe narcissistic wound ie. they have just been dumped. Even then, this is relatively short lived and is more of a "pity party" meant to garner supply from loved ones and friends in the form of sympathy and affirmation. Always the poor victim til the end. Whatever this man's condition (bi-polar?), it still is toxic to you. You have to understand that you couldn't fix or save him. You could help him but that involves great risks. He has to be willing to help himself overcome his depression and self defeating behavior. It is perfectly ok to put you and your mental health first when dealing with someone like this. Nothing to feel guilty about.