A hooker performed unprotected oral sex on me?

A hooker performed unprotected oral sex on me. We put a condom on and had sex. The next morning the shaft of my penis stings and burns. It has subsided a significant amount but still stings and burns 12 days past the exposure. I had a complete STD test panel completed two days ago- five days after exposure. Everything came back negative. There are no clear symptoms no blisters , no sores, no rash. The skin does not look red or inflamed any way. It does not hurt to urinate. Do you have any idea what is causing this? It still stings 12 days after contact. Many post around net have similar stories indicating this is some unknown virus that has penetrated the skin ( i did have a small nic from shaving in area night before)

Age: 53
Medications: gabapenten, nortriplyn, depakote