I think my bff is horrible
Why do you think that your bff is horrible?
He criticized me harshly because I borrowed his car, but now he nows that I have a family who owns a car.
I'm sorry he's being that way.  Maybe you should talk to him about it?  People shouldn't be horrible to others.
I think he's a loser and I feel sorry for him.
It's not okay for your friend to be extra harsh with you. Perhaps you should talk to him about the situation and try to understand where he is coming from.