That definitely sucks. Very sorry to hear that you are heartbroken. Horrible timing indeed. That is heart wrenching.

However, here's the thing. He was placed into a codependent role with you being a guardian of sorts. If he got fed up with that role and with how you are, there is very little that you can do or say to change his mind. This all seems to stem from your own issues and then an issue together with the fighting.

Why were you fighting? What were the fights about? Fighting is not a good sign of good things to come.

This may sound harsh, but perhaps you need to be alone to resolve your own issues of control and OCD before getting into a commitment with someone. That's what I would suggest. Do you have a therapist?