Hi and welcome to the GERD forum
Stepping off PPI's can be tricky due to the rebound symptoms...and needs to he done slowly....as the above poster mentioned see your Dr for the best course of treatment.
I have had Gerd for years. You should see your Dr. If the acid reflux is bad and it comes into your mouth, it is possible to cause sores, although I am not sure.
Better to see your Dr to make sure. I hope it all clears up soon