Is it oral herpes or just a bad coldsore?

okay here's my situation. i gave head to a friend out of curiosity. he said he was clean. a few hrs later i felt a copper feeling in my mouth like a penny. then my lips started feeling sensitive and my lower lip got a rash it looks like. there are no bumps just little red spots on my lip . ive been brushing my teeth and rinsing my mouth with mouthwash like insanely and it feels better than it did but i still have it . last night before i went to sleep i dipped my lower lip in listerine for 1 min then put some neosporin and went to sleep. when i woke the left side of my lip felt fine and the little red rash was disappearing. but i still have it on the right side. sleeping alot seems to help but i still want to get tested