Hi tascott2
Great info already shared here. I would add a couple ideas. One, keep a journal of all your food you eat every day with the goal of 2500 calories. Having to write it down and report it to yourself and your support team keeps you accountable. Weigh yourself every day at the same time in the same clothes and write it down. Again, accountability. May I also suggest you keep a journal of how you feel, medical notes, questions, etc. Take it to all appointments so when a thought or memory strikes, you can capture it. Use it with the doctor appointments to make sure you get all questions answered. Eat heavy now, try to gain weight during the first 2-3 weeks of treatment so you have reserve going into the last weeks.
I also suggest staying somewhat active. If you normally walk or jog or bike, step it down a notch or two but still do it when you feel OK. Don't burn too many calories but I would resist the urge to stop exercising. Walking around the block with a loved one can help your mood.