Responses
"can't take it anymore", as in, see Miki hurt himself because of what he (white-haired dude) has said in the past because he was playing along with Miki, saying they were sex friends even though he was already in love with Miki and loved him for who he was
From how I read it, they both love each other and they both suffer from it; there's guilt among their feelings but I wouldn't say pity.
I hate him! (︶︿︶)＝凸
He says:
"I can't take it anymore, wish we could go back to that day".
and then on the end part says that "I love you, I really love you".
Seems like he's staying with Miki out of guilt and pity.