I have a friend going through something similar but she is fairly recently out from a non-cancer, non-throat surgery, no radiation at all. They think it might be her thyroid going wonky ... but there are a lot of confusing allergy symptoms appearing too. (The results keeping alternating between yes allergies and no allergies ... driving her nuts, as you can imagine.) Because what you are describing sounds so much like what she's going through, I'd really ask about thyroid related issues ... I know the rads did a number on my thyroid right away.
I have very little real experience with this, of course, and I do hope others chime in. The only person I've met in real life who stayed on a feeding tube was an in-law, and to my understanding, whatever her condition was, she simply never got off the feeding tube in the first place and gave up hope. Very different scenario. (She's no longer with us, so I can't ask her the details ... she was very old.) She never said anything about throats or swelling ... I wonder if I could get someone else in the family to clue me in on more details.
I've been waiting on my dentures for about six months now (due to some funky issues with my surgeon) and nobody seems to be batting an eye at how much weight I've lost or the fact that my diet is crap. I suppose if I had more severe symptoms like you, they'd be paying attention ... and you're totally right to be concerned about that. Whether you need a tube or not, the issue needs fixing because that is just plain miserable. You need to be able to breathe too! That's the part that bugs my friend the most.
Do allergy meds help? Have you tried an inhaler (if you have one)? This has been a rough season for breathing for me, and I've used my rescue inhaler more times this season than I have since I was issued the thing. Oddly, though I'm not sure at all what the issue is, except my palate dropping while waiting for the dentures, it does seem to help ... which argues for swelling in the airways, at least. If you have an inhaler and it seems to help, consider inflammation as a possible part of the problem.
No, I am NOT a medical specialist, just a confused patient like everyone else, but these are the things I've been seeing and experiencing, so maybe some of it will help.