Well, based on my experience just let him go. Someone who truly loves you wouldn’t treat you like that. Stop asking questions and wondering to yourself Why he wouldn’t change for you. Clearly he has problems and need to fix himself first. I understand you love him so much and care about him so much and that’s okay. Things just have to end. Just accept it. Be grateful for the happy memories u had together. Stop trying to understand and change things you cannot change. Just let it be and let it go. You’ll have peace of mind.Cut all communications With your ex. Just walk away. I know it hurts like hell but in time you will heal and be happy again.