Eve,
I too thought I'd tough it out. Didn't want to get hooked on painkillers. What an idiot I was!
A very caring and experienced Oncology nurse put it to me this way. "Your cancer won't go away any faster by you being in pain, and you will impede your recovery by not getting enough nourishment and hydration, so you'll just hurt longer," Once we got the pain under control (and I got up to the 125 microgram patches, supplemented with liquid morphine prior to meals), I was able to get adequate fluids and nourishment down. Addiction is not an issue. There is some withdrawal as you wean off of the meds, but it is nowhere near as unpleasant as going through this without the medications. The next few weeks can be brutal. He needs to get the pain under control and start eating.
It WILL get better, but how long that takes will be affected a great deal by how well he takes care of himself.
He will come around to appreciate the love and caring that you all have shown. Be patient.

Good Health

Chuck