HI, thanks for using healthcare magic
The mouth sores may be
aphthous ulcers which are a type of ulcer that can occur in the mouth or may be due to cold sores.
Cold sores are caused by herpes 1, not sexually transmitted and it is very common.
Hand foot and mouth disease,
iron deficiency and low levels of b12 can also cause mouth ulcers
The sores usually resolve, this can take a week to 10 days. Pain medication such as
ibuprofen,
cataflam or
naproxen can be used to help reduce your discomfort.
Cold liquids or ice may also help.
You can also consider sprays/gargles such as covonia throat spray, chloroseptic spray/gargle or diflam.
These are normally used for sorethroat , they contain an antiseptic and pain killer.
They can be used for mouth sores as well.
I hope this helps