Clinically, it very much sounds like Herpes labialis (cold sores; fever blisters). It can be triggered by sun exposure, fever, and stress (among other causes). Burning, itching or tingling sensation occur even before lesions appear. An outbreak in lip area starts with small blisters (vesicles) filled with clear yellowish fluid, on a swallen, red, painful area. Blisters burst and ooze. Finally, yellow crusts form.
Herpes labialis can be treated both topically and orally with anti-viral drugs. Untreated, the symptoms will go away, but slightly slower. It is important to prevent secondary bacterial infection too (antibiotic cream).
Dr. Jasmina Jankicevic
Do the lips in my pictures support that though?
Or could this be anything else?