I had the same cancer and similar treatment. *Everone is different!* but here is my experience. For me the second chemo was the hardest. By the end you're just in survival mode. I argued and fought against anti-depressants and felt immediately better after starting them. They and pain meds are tools to help him get through this. If he is still that low, inquire about changing or adjusting meds. Don't get me wrong, it will still suck. You just need to lower the suck level a bit so he keeps his head up.

I remember telling my wife "I'm not gonna make it" and the next thing I remember is starting to feel better.