you could have an infection called cellulitus ( dont quote me on the spelling) all it is is an infection under the skin go to the docters and ask for strong antibiotics.
you really need to seek medical help asap,please go to the er now,let us know how you gets on
First of all, you don't need an "appointment with a dermatologist".
You need to be in an emergency room as of five minutes ago.
There is something called death. You stop breathing and the flies lay eggs and your family spends a lot of money on the funeral.
(1) You have a life-threatening problem.
(2) re-read # 1
It is impossible to diagnose without an in-person examination, but the liklihood is you will require intravenous medications.
Don't wait until tomorrow.