I burnt my mouth on hot chips, got a blister in my mouth n it was sore. over the next few days the pain has spread to me jaw n pain & stinging?

Possibly infection: Damage from a burn has a number of effects. Swelling from inflammation occurs & can push on nerves in the area causing the pain to spread. A burned area is susceptible to infection & pain progressively spreading outward from a burn should be looked at by a medical professional. The mouth is full of bacteria, & jaw infections can get nasty if left untreated.

Can't tell: Can't tell over the internet if you have a localized burn that will self-heal, or if you have done more serious damage. Best advice: Call your Dentist for an examination, diagnosis, and treatment plan. That's what your Dentist spent all those years training for. Call a Pro.