Did you get the surgery done?
It seems like a mix of chronic tonsillitis and some oral mucositis, probably secondary to your gastric symptoms.
If recurrent tonsillitis, surgery might help. But it won't resolve the symptoms associated with mucositis and gastritis.
Next Steps
I wouldn't be able to comment much without examining, if you could come for a consultation I might be able to get a clearer picture.
Health Tips
Try including some multivitamin tablets in your daily routine.
if you feel excess acidity, get treatment for that.
and some local steroid ointments might help with the burning symptoms.