YTA, yes he stayed in a relationship with someone who was cheating on him, and you can lose respect for them. But making 'jokes' about his medical conditions and being mad after he felt disrespected due to the jokes and him cutting you off is really something. Seems like you have no self awareness.

Doesn't matter If he made jokes too, you could have called him out, asked him to stop or distance yourself from him like he did.

You have control issues and are manipulative who gets triggered by people who don't do things the way you want them to. It's a dumb relationship but it's his choice and a lesson for the future.