@kamrin
Make certain you have thrush. The mouthwash prescribed when my radiologist thought I had thrush, as well, was burning upon burning. I went to urgent care. The nurse said, "ouch." then covered her mouth. A young innovative doctor said that oral thrush is the same as the yeast infections women get, so he took a swab of my throat and the test results came back negative.
Just be patient. Eat whatever you can. I sipped smoothies through a long straw and hated them. Drink Ensure - it'll go down. And, as soon as you are able to tend to your oral mouth care start a routine. It is miserable and painful, more than I have ever experienced in any other health issue in my life. But, you will heal and gradually be able to add foods that you can eat. I'll never take eating, tasting, and enjoying a good meal casually or without gratitude, again.