Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain Canker Sores can occur due to a number of causes and can be due to causes like deficiencies of Iron and
Vitamin B12, allergies to any food or medicine, stress,
acid reflux,
hormonal imbalances,
dry mouth..
Infections like Herpes can also cause blisters in mouth..
I would suggest you to consult an Oral Physician and get evaluated and generally Canker Sores are diagnosed with clinical evaluation while if any other cause is suspected Oral swab culture,
blood test etc can be done for diagnosis..
As of now you can start taking Vitamin B complex supplements..
Apply numbing gel containing Lignocaine over the ulcers or Gargle with numbing mouthwash..
Avoid spicy and hard foods..
Do cool water rinses and suck ice pops..
Hope this information helps..
Regards.