I’m very sorry for what you and your dad are going through. My brother in law did not have any chemo. He just finished 4 weeks of radiation. It was rough to go through and now he continues dealing with the side effects. I haven’t heard yet what comes next. It’s very hard to help or comfort someone with a serious diagnosis. There so many unknowns. Don’t give up. Read the book Radical Hope and try some of the recommendations. Consider changing to a whole food plant based diet and no sugar. That includes artificial sweeteners and alcohol. You can checkout drmcdougall.com for more info on the diet. Most oncologists never mention diet. Feeling helpless is devastating but try to focus on the things you can do for him if he is willing. I found Qigong meditations very helpful. Some people follow a fasting regimen to help withstand the chemo. There are YouTube videos about chemo fasting. I wish I could be more help.

My husband was diagnosed with stage 4 larynx cancer in 2021. They gave us very little hope. He had 35 radiation treatments with chemotherapy. He was diagnosed while in ICU after a major fall. He had been misdiagnosed twice for the cancer. So sad. They said he wasn’t going to make it through the treatments because he was too weak but he did. He is cancer free. However has a feeding tube. He can’t swallow anything due to aspiration. So there is always hope! Don’t give up.