Also try tailoring your intake to stuff you feel may help or be soothing. I remember when I was going through it everything - even my own saliva felt like acid hitting the back of my throat... I would cringe when I knew something was going down and then wait for the burn. Then one day a few months out... it didn't happen. It was such a relief. You will get there. Healing from rads and chemo is a long term thing (well mostly rads as chemo generally dissipates in a few months) Have you tried Manuka honey? It burns like a bitch but it's soothing and healing and has a whole bunch of other benefits. It can't hurt (on a medical level) and it might help. Also try saline rinses and perhaps some flattened club soda. All have the potential to heal, and the club soda and manuka you can swallow.

Also try and adjust your pain meds so that you take them just before you eat if it's possible (usually they take 15 minutes to 30 to kick in), or even ask for magic mouthwash swish (and swallow if your formula allows) once you're numb try drinking some nutrition - maybe a protein shake or smoothie. Avoid things that are acidic. I lived on pudding, and protein shakes etc... Being able to do this will help you feel more normal and likely brighten your spirit. Hugs and welcome.