Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain if you have a persisting ulcer that does not improve then there can be chances of malignancy causing cancerous ulcers as you already have a history of tobacco and pan chewing..
In case if the ulcer recurs and heals then it can be a recurring apthous stomatitis
causing burning and inflammation of the tongue and also causing ulcer.
It can be caused by a number of causes like Vitamin B12
and iron,tobacco chewing habit, stress, hormonal changes,acid reflux
In case if it is a persistent ulcer that is not healing at all, the you need to get a Biopsy done to rule out the exact cause of the ulcer and treatment can be planned accordingly..
As of now you can gargle with numbing mouthwash,take multivitamin
tablet daily, suck ice pops and gargle with cold water..
You can also take Ibuprofen for pain..
Avoid chewing pan and tobacco and also avoid spicy food..
Maintain a good oral hygiene
Hope this information helps..
Thanks and regards.
Dr. Honey Nandwani Arora.