Welcome @blacksabbath, Mouth sores can be pretty miserable. There are a couple of other discussions where you can meet others with similar symptoms and learn what they have shared.
--- Burning Mouth Syndrome (BMS): Anyone found any relief?: https://connect.mayoclinic.org/discussion/burning-mouth-syndrome-2/
--- Sjogren’s Syndrome – Introduce yourself and meet others: https://connect.mayoclinic.org/discussion/sjogrens/.

Mayo Clinic has some treatment information that may be helpful here:
"How do you treat Sjogren's mouth sores?
Yeast infections in the mouth should be treated with antifungal medications. Treat systemwide symptoms. Hydroxychloroquine (Plaquenil), a drug designed to treat malaria, is often helpful in treating Sjogren's syndrome. Drugs that suppress the immune system, such as methotrexate (Trexall), also might be prescribed."
--- Sjogren's syndrome - Diagnosis and treatment: https://www.mayoclinic.org/diseases-conditions/sjogrens-syndrome/diagnosis-treatment/drc-20353221.

Has your doctor suggested any treatments like antifungal medications to help with the sores?