Need Help,Can't figure it out

I am not sure if i am barking up the right tree but i have found so many posts that have similar symptoms as mine. Quick background to my situation: I am 31 also circumcised. I had been on a long trip away from home. 3 months ago i got drunk one night and ended up sticking my hand under a woman's panties, did nothing invasive but touched the top of her labias around the where the clitorus would be, once and for a couple seconds.  No, girl touched me down there, there was a time i can remember a girl stuck her hands down my pants but not under my enderwear. This was the only exposure event, i later left the bar with my friend and we ended up back at our hotel. I go and pass out in my room, wake up and like and idiot i decide i need to masturbate and end up mastrubating excessively over the next day to day and a 1/2. To the point i was sore and irritated. The issue i am having i thought was some std but i can't for the life of me figure out how, unless i gave it to myself from touching myself during my idotic masturbating period(oh, by the way i was always washing my hands).  About 7-10 days later i started to experience what i can only describe is burning on the head of my penis and in my groin(scrotum) like i had put "icy hot" down there. Beginning of the freaking out. I have been freaking out about all nature of stds from herpes to hiv though i can't see how that is possible. I went to the unit doctor right away in a panic, explained the circumstances, he didn't think i had anything to worry about and did a unine test and it came back neg for any white blood cells which would indicate an std infection.  That was a comfort. I end up getting worse over the next month and what was at first irritated skin at the head of the penis and some swelling started to later have lots of pain as well. It was like the skin irritation and redness went into my urethra hole if that makes any sense. I saw another military doctor,(over 1 mo of incident) family practitioner and he said he didn't see anything that out of the ordinary(they all have been saying that) he ran me on a full std screen, bore punch, blood tests for(clamidia,syphillus,hepititus,hiv,etc) which all came back negative.  Around this point the pain in the head of my penis was excruciating, I was eating 800mg ibuprohpen like it was candy and not much help. Not only that but i was having horrible guilt about the whole thing and the fact that something was wrong down there was just making it all worse. My symptoms/problem occured close to that stupid night and that the coincidnece keeps bothering me, despite how it seems there couldn't be a connection. I get back home and come clean to my wife about this whole mess. That helped me put most of the guilt behind me and now we have worked things out i am just 100% wanting to get this thing figured out. Saw a urologist, still worried about the std thing(can't seem to get that out of my head) and he said that from my story and the results of the last screening there was nothing to worry about. What about the pain? he like many others kept saying it was in my head....and then after went back a day later saying i needed something he put me on a week of dioxycycline and a few days of peridium. Nothing came of these and so then i went to a dermatologist, thinking i had some rare fungal/bacteria infection of the skin form that dang country. he told be to use hydorcoritzone cream. did that for 2 weeks then went back with litle to no change and his next great advice was stop doing everything and just see what happens i see him tomorrow after about 3.5 weeks. Meanwhile i have been getting crushed. I am not having sex because the fact that something is wrong with my penis still worries the heck out of me. So, i found the posts on this site, and have since been taking some of the advice i have found.