There are oral liquids that kill the pain, but you won't be
able to taste food. They're normally used for gum , denture and tooth ache: Pain-A-Lay and others a pharmacy might know. active ingredient benzocaine, lidocain,...<anything>cain
They make treatments for herpes virus but they take a while
to take affect. Most are some form of Acyclovir, for example Valtrex is just time release acyclovir.
Oral and genital herpes are cousins, and are often set off
by emotional distress, or a change in the body's chemestry,
for instance going on-cycle and upping your testosterone suddenly, or at the end of a cycle and testosterone drops.
I've seen studies that indicate herpes viruses are sensitive to the ratio of L-Lysine(depresses the virus) to L-Arginine(increases the virus). Some people get "fever blisters" when they eat foods high in arginine, like pecans and other nuts, or the new amino acid HGH releasers.
I've seen recomendations to take 5 Gm L-Lysine a day till symptoms dissappear and then 1 GM (one or two pills) a day thereafter for continued suppression.
Another cause of fever blisters is a change in the flora of the stomach and intestines such as after taking a round of penicillin. Kills the beneficial bacteria and the herpes breaks out. The best for this is eating/drinking live active culture yogurt (not pasturized) which re-establishes the good bacteria. Hope this helps.