Skin on Groin thighs lower stomach won't stop burning

[Krjjah]

I am male. 35 years old. I have had sex with 3 people within the past year. Condom used everytime for intercourse. Received oral with no protection.  

Off and on for the past 6 mos I have had a burning, maybe even a tingling sensation on my skin. This occurs on the tops of the thighs, the inner thigh, The groin, below my belly button but above my penis.  The crease where the legs joins the pelvis.  It feels as if there is a heating pad on my groin.  It gets worse with time.  Lasts from a day to a couple weeks at a time and then goes away.  Had an mri which shows no nerve problem.  Doctor said it isn't herpes because there is no rash or lesions.  Could it be herpes? A skin condition? Anxiety that it is an std? It is very uncomfortable.  Thank you.

[Krjjah]

I also want to add that these episodes come and go.  But they are getting more frequent and more uncomfortable.  No sores, blisters, rash or lesions. Just the burning sensation. I have been told by my doctor that this sensation always results in blisters a couple days later if it's herpes.  But since my symptom, the burning, continues for a week or two with no sores, that's it's not herpes. Is he wrong?I am beginning to have quite a bit of anxiety over it. Which may be the cause.  I'm really unsure.