Personally, I would be grateful for this situation. It’s painful now, but in the end, consider it a godsend. He gave up a relationship with you over a crush that may or may not work out. No one who loves you would do that. Crushes are normal but he actually thought that pursuing it was worth losing you. You need to go no contact. You shouldn’t be seeing him at all until you can handle it. You can still hang out with your friend but make it clear if he’s tagging along you can’t be there. Eventually, your decision on whether or not you even want to be her friend is up to you. You’re not obligated to be friends with anyone if it makes you uncomfortable.