Fever blister in between my lip and nose. on the skin. just appeared. ?

Confirm Dx, get Rx: Are you sure it's a fever blister (oral herpes)? Had it previously with the same symptoms? If so, then pretty sure you have it again. If new, see a doctor ASAP to confirm the diagnosis. Effective treatment can speed healing of recurrent oral herpes, and it only requres a single dose of drug (valacyclovir), but must be taken within 1-2 days of onset. Either way, call or see doctor immediately.