this is Dr. David
I can not examine your mouth or abscess
do you have a history of smoking and drinking alcohol? these can increase your risks for oral cancers.
a large abscess needs to be biopsied to see if there is cancer cells in there.
you need oral antibiotics or IV antibiotics to help fight the oral infection for the abscess to get better
you need to see a doctor right away about this
you can go to your local hospital or A&E department and have a doctor there start you on antibiotics.
you should be rinsing your mouth with salt water as often as you can to kill bacteria in your mouth
the A&E doctor should give you pain medications as well
let me know if you have questions.