@lunatuna, great question to ask. My wife, Kate, got me through a long tongue cancer treatment of surgery, radiation and chemo about a year and half ago. I simply could not have gotten through it without her. I think the most helpful things she did were
1. Encourage me, hang out with me, keep me away from despairing thoughts
2. Feed me: I never felt hungry, could not eat solid food. Kate made me eat. If you are going to bother with Boost, might as well get the good stuff, the "530s" as we call them. I still buy a case per week of this:
https://www.amazon.com/dp/B0B1HJL9QK?psc=1&ref=ppx_yo2ov_dt_b_product_details
3. Administer the meds-- I could not keep track of them
4. Distract me--Kate would try to get me out and walking, go shopping in a mall, walk to get coffee, watch Netflix, walk to mass, etc. My inclination was to do nothing, which is not good. Kate even gave some chores to do, in a kind way, just to keep me occupied.

Anyway, the whole thing brought us closer together. I'm glad it all happened. Kate's attitude was, "Lets make this an adventure, and do it together!" And when I was well enough, we took a vacation together, without the kids for once, and it was magic. God bless you.