Although he might not seem like he cares, some people don't show obvious emotions. Many people hold in their emotions. It seems like you two had a fight, which he might still be numb from it. After a fight or repeated fights, it can leave both parties eventually numb and the feeling of not caring. Even though this might be, it doesn't mean he doesn't care.
On a different note, it's important for you to stand up for yourself. You haven't done anything wrong. If he's acting distant, you can't force him to stop. If he doesn't want to talk to you, don't talk to him. I do understand that it's difficult, but you should only keep positive people in your life. I know you are reminded by how he used to be, but if he really did change, you have to accept it. You can't expect him to change. I recommend taking some time for yourself. Get away from this negativity