That is a hard one, honestly as someone who has been health all of their life I don’t think I can comprehend what your going though and can’t put myself in your shoes.
Sorry this will be the most boring answer but personally I would spend my final days with my family and friends. I don’t think it really matters what I do with them. We could go on a trip or say home and binge watch a TV show, go out to eat play video games whatever.
I do think I would continue to try and figure out what is wrong with me. I am naturally curious and want to try and fix things or at least figure out the cause. I would probably grab a Steam Deck and play some games at the hospital. Kill two birds one stone.