Is it bad that I can't even look at my ex girlfriend?
Did things end badly between you two? Why can't you look at her?
Because she still hangs out with losers
Ending a relationship is hard but you should stop focusing so much on what your girlfriend is doing. It will not help you lead a good happy life.
I just don't want her to get hurt, but that is hard to do when I can't look at her.
If you two ended things as friends, it's great that you're looking out for her safety now. Consider telling her that you are worried about her actions and the actions of her friends.