Why am I having this one-sided head to toe nerve pain?

Hello,

Welcome to icliniq.com. I can understand your fear. If you have used a condom while having intercourse, then it is less likely to acquire a sexually transmitted infection. You can either have an ulcer over your genitals or pus from your urethra in case of sexually transmitted infections. Since it has been five years now, the chances of you having any infection with no symptoms are very remote. Moreover, you have tested yourself for HIV (human immunodeficiency virus), syphilis, and herpes. All are negative. The only thing which can remain silent and lead to a problem is syphilis. It is called neurosyphilis. Again it should have been picked up in VDRL (venereal disease research laboratory) test. With your history, I do not see any reason to worry about sexually transmitted infection or HIV. But thorough physical examination is necessary to declare you are infection free. I would suggest you visit a venereologist for a physical examination. Regarding your nerve pain, if it is pain restricted to one half of your body, you need to see a neurologist.