The blisters on tongue and cheeks may be of aphthous ulcer type which is recurrent in nature.
I would advice you to maintain oral hygiene
Take plenty of fluids and nutritious rich diet.
has to be administered.
Maintain oral hygiene well.
Use warm saline and chlorhexidine
mouthrinse to gargle.
Avoid intake of spicy,salty food items.
Hope this helps.