Warm sensations throughout my body

For the last month and a half I have experienced weird warm sensations all over my body. Sometimes it appears in my inner thighs, other times around my tailbone, and recently, around my testicles.

When I touch the areas of my body, it is hard to tell if the skin is warm. Almost feels normal. But I can feel the warmth in areas being affected.

All of this started after I cheated on my girlfriend. I had unprotected intercourse with a woman I did not know well and the next day I developed flu symptoms and I had the urgency to constantly urinate.

Long story short I had three STD tests and three HIV tests. All tests came back negative. One HIV test taken could detect early traces of the antibody soon after infection. But as mentioned, I was negative.

I was certain I was HIV positive. I had some symptoms. I drove myself crazy researching online for answers. After I found out that the advanced HIV test was negative, I thought I would feel better. But I didn't.

Besides the fear I was infected with HIV, I never told my girlfriend I cheated on her. And during this time, the stress levels at work were growing and continue to grow.

So what am I feeling? Was I infected with some strange bacteria or unknown disease?  I know there is something wrong, so how do I cure it?

Anyone else feel warm strange feelings in bodies?