As your medical history you are taking finapecia and zenoxa 150.
Finapecia cause constipation, which is also a cause of ulcers in mouth. I think reason of your problem is constipation and stress due to your medical condition.
Next Steps
Try to reduce stress by doing medication, yoga, you feel better and energetic.
To reduce constipation -Drink 2-3 lit. of water
Add fibre to your diet like oatmeal or green leafy vegetables to keep bowel clean. Avoid junk food.