Thanks for sharing your concern.
when you have already visited ENT doctor and dentist
, and they have suggested you that it is not cancer then you should be relaxed,that it is not cancer.
Now i would like to ask you why do you feel it is cancer?
it has no such signs and symptoms,which could be correlated to cancer.
you have already mentioned that it has arised from the self induced injury
now the symptoms, that you are experiencing like swelling and heaviness that is just due to tissue injury and inflammation.
once the tissue repairs or heals you will feel absolutely normal.Also you must avoid this habit further.
Regarding your bad breath
, that is due to improper oral hygiene
or chronic sinusitis
.You must rule out these too.
use antiseptic mouth wash for 15 days twice daily and look for the changes. I am sure you will be fine.
Hope it helps.