Kerri, I'm not sure any of the "whys" of cancer will ever be known. Each of us is different. I can tell you, though, rapid weight gains or losses can impinge nerves as can scar tissue/fibrosis. In addition, the part of our brain that processes taste gets affected by chemo and radiation. Some people never regain taste at all.

I'm probably not the comfortable solution but my approach is to increase the problem taste until the body adapts. Our mind will allow us to completely transform our tastes, if we are accepting.

The common ingredient in everything you listed is acid or vinegar. Ketchup was the worst and longest for me, next to Ranch dressing. Dark chocolate is the only chocolate I now enjoy but it hasn't been the same for 11 years now. To "reprogram" my tastes, I use visualization and remember what it used to taste like.

I have had the same sensitivit, as you describe on your tongue, only it is the back of the throat that got the most radiation. It just starts randomly stinging at times.

I tread softly on this, but you need to address the things bothering you with a professional. There are signs some of this came with you on this cancer journey. The worrying and constantly taking notice of the differences needs to go away. It can't do anything but stall your recovery. Just my opinion.