Hi,
I assume that you have this problem at least for few days.
If it is gluten allergy you must have noticed immediately after intake.
Taking Heavy Antibiotics - without associated Lactobacillus may also produce like this due to deficiency of vitamins. The way you have expressed your complaints goes in favor of fungal infection in the mouth.Treatment:
Anti Fungal local application ointment or liquid,
Anti Fungal Oral Tab
Vitamins
Antibiotics, as there may be associated infection
Maintaining oral hygiene
Best Wishes

hi,
I have read your question,
By the Symptoms you have given above , the issue could be due to fungal infection, vitamin deficiency , sensitivity to toothpaste , or bacterial infection.

Symptoms of gluten sensitivity may include bloating, abdominal discomfort, pain, or diarrhea; or it may present with a variety of extraintestinal symptoms including headaches and migraines, edema, lethargy and tiredness, attention-deficit disorder and hyperactivity, muscular disturbances as well as bone and joint pain.

Since you didnot mention any , I think the posibbility of a gluten reaction is less,
I suggest you to take vitamin rich foods like citrus fruits , indian gooseberry , green leafy vegetables etc.
Along with it take antibiotic and anti-inflammatory tabs(until the soreness reduces) and multivitamin capsules atleast for a week.

I recommend you to consult a physician nearby for further guidance

Wishing you a good health,
DR.G.Gayatri devi.