A friend who asks how you’re doing, instead of talking only about himself, is a friend with the mental well-being to think about something other than himself.
Don’t applaud him for being selfless. Instead, applaud him for being well put together and capable of coping with life. THIS is what makes him a good friend. If he only cared about others and pretended to care nothing for himself, then his lack of self-respect would prevent him from being worth your time.