Your best answers are your doctor(s). Sometimes it's a combination of ailments like mucocitis, thrush, bacterial, viral infections, inflammation, that needs to be treated with different medications, some oral rinses, pain meds may be simililar. To check the thyroid a TSH is done, and should be at least 2x a year since chance of hypothyroid dysfunction can increase the further you are out from radiation. In addition, other tests should be done, monitored that may be effect by treatment, energy, organs, like creatine, Liver, D-3, RBC, WBC, Hemaglobin, B12, glucose, testosterone, and others. 8 weeks post treatment is still early. Radiation continues to work just as long as radiation does, and some cells take months to recover, and metabolism can change fighting cancer, repairing body.

I don't know if they would do HBOT or even be approved, but it's being used more often for radiation patients, under what circumstances, not sure all, but unhealing ulcers, osteoradionecrosis, prior to tooth extractions post rads, are a few, but they don't do it unless they know you are cancer free since HBOT can feed cancer. I need it, but have to wait until Chemoradiation is completed, an probably not until a three month clear scan.

Maybe see a nutritionist about getting adequate nutrition, hydration, which goes by our BMI, height, weight, activity levels, and others, so each person is different. The same with water, which basically comes down to half your body weightin liquid ounces, daily, if not more. There are on-line calculators that can give you an estimate, but our health care providers can answer best what your needs ate to repair, recover, which can be as much as 1gram of protein per pound weight, 1/2, and again they use nutritional formulas. Sometimes excess protein puts a stress on the organs, if they are already compromised. If the doctor approves, physical therapy can be useful to get you out of being de-conditioned, before jumping into a full scale exercise program. The YMCA has 11 week LiveStrong programs for Free throughout the country for cancer patients, if one is in your area.

I hope this helps.