I have, definitely had an accident like this before. There was one instance in my life, where I really burned my mouth, just as you are describing now, but fortunately I can not remember the year, month, or anything more about it other than, "ouch, I've totally done that too."
The mouth seems to heal pretty quickly, but if you have burned it, as bad I think, you may be in for a week of, "damn it, this sucks."
Ice cream, or sorbet, loads of iced water, and avoid solid, hard or sharp food. No chips, bread, crunch cereal, fried chicken or fish... basically, "nothing crispy."
You can eat mushy meat.. for example, "southern style bbq ribs." not too spicy, not hot off the grill. + green salads for a week, should do you well...