From my experience of caring for my daughter, while she was on a 3 week chemo regime, day 1 chemo she was ok. Day 2 rapidly downhill sleep when she could eat what she fancied if it was quick. If she had to wait she no longer could eat the food, days 3, 4, 5 gradually getting better. Walks when she could relax, sleep when not. Then week 2 and 3 feeling almost normal. She couldn't be bothered with normal things in the first week. But every cancer, every chemo is different. My only advice would be be led by your husband but take care on that second day as the effects came on suddenly and fiercely. My best wishes for you both and no euphemisms from me, they don't help. Treatment can be hard.