Effects of NOT wearing a mask while using a palm sander???? Sore throat?

About a week ago I was doing some work on the bathroom wall. I patched a hole in the drywall and the next day I used a palm sander to smooth out the surface. I was anxious to get it done and I did it without a mask. There is no window in the bathroom so there is little ventilation. It only took about 30 seconds. Within a few days my throat slowly became red and had white flecks on it and kind of ulcer-looking sores on the roof of my mouth. It really didn't hurt much. It just felt difficult to swallow - like my throat was swollen. I thought for sure that I had Strep Throat by the looks of things, but the Strep test came back negative. In the past couple of days, the sores and redness in my mouth/throat have gone away. Now I have another symptom, but I'm not sure that it's related or not. When I swallow food my esophagus is super sensitive to what I'm eating (it burns a little during and after). And after I eat, it feels like there is a marble stuck at the top of my stomach. What on earth is this? Do you think from sanding the wall without a mask?