Now that he's in the position where he needs you, I'd recommend having a little chat with him and telling him that it's going to your way. I'd also tell him how he makes you feel when he says these things. If he's going to be cared by you and your going to around him more often then there has to be some sort of agreement and compromising, that way all goes peaceful. Of course you have nothing to do with the disease....nature is control over diseases like this.

I hope all works out and you don't let this get to overwhelming.