It's just about the person. If you're all around secure and have a healthy mind, you will joke about this stuff and make the best out of it. If you're fucked anyways why not laugh about it?
I kinda feel like OP is kinda trying to be a victim here when he got what was expected. Its a very shitty treatment, from a shitty person - no surprise here. Why even engage him?
And I feel like I have to mention I went trough some shit too, bone marrow transplantation. I was fat af and I was malnutrished at different points during the sickness, I lost my hair and looked like somebody fucking injected me with synthol... Everywhere. Guess what, I still appreciated an "asshole" joke from anyone.