I'm not going to support my friend
Why don't you want to support your friend?
He has been a bad friend to me for a long time.
Even if he has been a bad friend for a while, there may be a reason behind his behavior. Have you asked him about your concerns about his behavior? Supporting him through possibly difficult times like this will show you are a true friend.
He needs to prove that he's sorry. He should be the one trying to work things out with me first.
I understand your concerns. Sometimes you just have to put your differences aside, sit down together, and directly express your concerns to each other.