STD (and which one) or stop freaking out?

Hello,

I am kinda a nevous wreck. I have been in a relationship for about 2 years, I did however cheat (without protection(falatio)) about 5 months ago. About 4 weeks ago, I found an open sore on my penis (uncircumsized) about the circumfrence of a pea. I chalked it up to the recent week of drinking, and roughhousing and assumed it was a small injury. But it took more than a week to fully heal. Then a couple days ago, another open sore opened up (about the same size/irregular shape), and I got cold or possibly flu like symptoms. I did research on the internet, and I thought it looked like herpes minus the "zits". Then with my cold or fever, I am worried that it could be syphilis. As of the first sore I did not have sexua| contact with my girlfriend since about a week prior to finding the sore. I pray tha I am just freaking out and it is dry skin sore (which I have had on my foreskin in the past) or some other stupid thing. Please help asap, I am ready to cut it off...come on, I am a man you should know thats a joke. But seriously worried. Pardon the possible spelling errors.
Thank you