I'm guessing you kissed this person a few times too? odds are it's just a run of the mill upper respiratory infection but see your provider. let them know you recently performed unprotected oral sex and ask for proper testing for std's on your throat too.
grace
Paranoia will cause you to not be on the ball. And most of the emotional/mental aspects of an STD are bi-products of knowing you have an STD so if you think you have an STD you are likely to experience all of these. You may have gotten a sore throat just from the fact you gave someone oral (depending on size and how rough you did it). Also if you really think you have herpes and the red is a sign have a doctor check it, Though my friend did have a giant puss ball in the back of her mouth and it was nothing to do with an STD though she had been giving someone oral.
first stop freaking out and start being logical