Individual reactions vary wildly but post TX fatigue is quite normal. Plus IMO an Oral Cancer patient would have to verge on being psychotic totally divorced from reality not to be DEPRESSED. But both my fatigue and depression never seemed to get better until I started on thyroid medicine.
While my CCC doctors were top notch on Cancer, for related issues like Thyroid - "not so much". I was not only extremely tired but also froze for two years, even in summer, and kept a winter coat on in air conditioned places yet I was constantly told: "Your TSH levels are normal" and I did not ask for the actual numbers or test results. Turns out however there is controversy over what is the right TSH level with labs having a 5.5, a 4.5 even though endocrinologists who went to Medical school the 21st Century consider 3.0 as the highest acceptable level. Before TX, I had a TSH of 1.6 and after TX it shot up to 4.3. Now that I am "on the pill", I am finally warm again. Plus my energy is back My TSH level went down to
3.04 on 25 mcg ,2.17 on 50 mcg and now 1.73 on 75 mcg. Of course there could also be nothing wrong at all with Gordon's thryoid . But it could not hurt to have a TSH blood test done. I only hope it's that simple. The rest of oral cancer certainly has no simple solutions.
finally, you are right that only caregivers and patients can truly understand the aftermaths of TX.
Charm