If your husband is not able to get enough calories daily, he will feel awful. Many people have gotten near the end of treatments only to end up getting an emergency feeding tube. There is also a nasal tube that could be used for a short time to help him get past the next few hard weeks. No surgery to insert it or to remove it. Tomorrow speak with your husbands doctors about upping his pain meds and about a feeding tube (probably a nasal one would be enough). That should help make it a little easier to get adequate nutrition in.