Hi, guy! Your story is somewhat similar to mine, especially being a husband of a lung cancer survivor. Yep, a lot of it was new to me, too, although the posting part was familiar because I had done similar for myself with prostate cancer.
On feeding, I had the same problem with my wife. The chemo tends to make taste lousy so they don't want to eat. Also nausea plays a role. I went to a lot of liquid things like Ensure, Breeze, Gator Aid, Smoothies, soft ice cream, etc. I would vary things around. Also, we went on a snack every two hours instead of a three meal day. This helped her eat something and minimized the nausea. My daughter called me the Food Nazi -- I would not give her the option to not eat -- I would give her two or three choices and insist she pick one. It worked for us. Liquid intake and nutrition are so important when under chemo and radiation to keep strength and stamina up. Good luck. Don