I am not a therapist, but I think it sounds like he is in denial about his own health. It's a defense mechanism and a self-preservation mechanism for him. He must care about you a lot though, since he worries so when you miss a dose of your medication. I would keep on trying to talk sense to him. Hopefully, he will wake up and take care of himself. You sound like you are doing your utmost to take care of him and his health. Take care.