No other pain medicine is as string as fentanyl. At my highest, I was up to 150 mg. That was right around the time I finished rads. If your husband does not see a big improvement in his pain after the patch has been in place 24 hours then tell his doc. Im just a patient but I would think he would need a minimum of 50 or 75mg right now. Just trying to give you a guideline in case he is only on a low dose of 25 or 50 mg. Its always better to slowly increase or decrease this medicine. Very important, no hot showers or baths either!
David is right with the calories your husband needs right now. Dont think he can make up calories or water the next day. Use the chemo lab for hydration. He still must continue to swallow every single day or he could have even bigger troubles down the road. I would drink ice cold yoo-hoo. It felt soothing in my burned mouth. Even though I could barely taste it, the yoo-hoo worked for me plus it has lots of calories. Another high calorie drink is chocolate milk.
As for the phlegm, try musinex or robotussin. You can check with his doc or nurses what would work to help. He might even benefit from a suction machine. Check with the nurses about doing that on his rad. visits too. It takes only a couple minutes but will give him a big relief after its done. Some people get a suction machine for at home too. Ask for one. Sleeping on a few pillows on on his side of the bed raised will also help with the mucous. The thick phlegm will continue for about another 4 - 6 weeks. Then it will be replaced with a dry mouth which will force him to carry a water bottle everywhere. There are some biotene products that can help with the dry mouth. Some people take a medication to help stimulate saliva. Thats nothing to be concerned about right now.
Even though you just found OCF, at least it was while your husband needed help. Some people dont find us until they have finished everything and are seeking help with after-effects. Dont worry, we will make the most difficult time alot easier for both of you. One thing that can help is think of anyone who offered to help you with your husbands illness. Let them help. Give them a chore to do and it will take some of the weight off your shoulders. It could be something little like walking your dog, doing a load of laundry, picking up a prescription, grocery shopping, or even visiting your husband so you can take a few minutes for yourself. Im sure you could use a break too.
Here is a list of easy to eat food that might be helpful to your husband.
List of easy to eat foods 
