Herpes or Not? Confused!!!

Hi, 33 year old sexually active male here. Have been having multiple (3) partners, protected and unprotected sex in the past 6 months. 1 of my partner is my girlfriend ( she's clean, she did her tests and have been with her for 10 years ), another one is a friend who i have been having sex with since november last year ( hadn't had any problems so far, have stopped now - she also did her std test) , and one very recent ( 4 times )( she claims to do full bloodwork every year and is clean ). A few weeks ago i had a pimple come out on my penile shaft. That broke and caused a few more bumps to turn up around the area ( like 5, not at the same time )(and not in clusters or cauliflower like arrangement ). Was sure it was herpes. Went to the doctors, the did a IGG blood test and a complete std profile. I was also given anti viral drugs. Everything cleared up within 5 days and my test results came back negative, with no antibodies detected. They left whitish scars ( underneath the skin )(i've got a dark complexion ) and all was well. No more pain, no more discomfort. Returned for a followup and the doctor said that it could've been a bad infection of the skin and everything looks in order. Two days later, i did have rough sex (unprotected with girl friend and 2 times protected with the last girl ) and i got it again at the same area on my penile shaft a couple of days later, this time started with one and ended up with 3 blisters.( again, not clusters ) Went back to my doctor and because my lymph nodes were swollen, he gave me broad spectrum antibiotics and told me that i could have a bacterial infection because the skin there was still quite vulnerable. I've finished the course and this time it didn't heal. It doesn't hurt as much but i can see that it's not crusting over. Also i feel a little feverish. And my testicles did hurt a couple of days ago. I really don't know whats going on. The blisters are flat, have a whitish middle, and reddish crater. One of it is healing now, whereas the other two that was close by has joined to form one large one ( half a centimeter big ). Returned to the doctor and he asked me to try a dermatologist as he thinks it's a skin issue, not an STD. But i also read that STD test can have false negatives all the time. I'm currently waiting for my appointment with a dermatologist next week, but am very depressed and hampered by my condition. Any perspective?  Please help.