Thanks for asking the query,
Your clinical symptoms and history suggest that you probably are having periodontal abscess
formation arising from the infected tooth.
Blisters in the mouth are due to some trauma due to biting , as a result of fever
some type of blisters are caused by herpes
simplex, allergies due to some foods, vitamin deficiencies .
Get clinical evaluation of the tooth , take an x-ray of the concerned tooth.
If it is due to abscess get it drained .
Avoid eating hot , spicy , aeroted , carbonated foodstuffs.
Use saline water gargles 3-4 times a day , use antiseptic mouthwash gargles twice daily keep the area clean . Take complete balanced diet.
Hope this helps out.