Having a tube in the stomach should not make your husband have nausea. He wont feel the tube at all inside his stomach.
I dont think your husband will be able to go to work for at least 2 or 3 days after having the feeding tube placed. To be honest, most patients feel like they have been punched in the stomach so hard its like their breath has been knocked out of them.
There are hundreds of prescription formulas on the market. They provide a complete balanced diet. I guess it would be possible to create your own formula at home. My concern would be getting all the daily nutrients in and knowing the calories to ensure he gets enough every single day. I have a sensitive stomach too and it took a few formulas before my nutritionist found the right one for me. Other factors that come into play with a sensitive stomach are the speed and consistency of the formula. Usually slowing down and adding water will help make the formula easier to tolerate.
To me it sounds like his intake is going to be a struggle. Every single day he should be taking in a minimum of 2500 calories and 48-60 oz of water. Less and he will have a difficult time getting thru treatments. I cant stress those numbers enough. Ive helped hundreds of OC patients get thru their treatments and have seen what skimping can do. I was a skimper myself and it caused malnutrition, dehydration and ultimately a few hospitalizations.
The link below has alot of good info. Its still under construction so not everything in this section has been finished yet.
Feeding tube info