The fact that this has resolved makes it a bit harder to sort out. I will make several comments which I hope will help but at this time, it sounds as though the process has, in large part, resolved and thus the most appropriate next steps may be to wait and see if the process recurs. If it does, you should see your doctor ASAP and get any lesions present tested, including a culture or PCR tests for herpes. Additional comments:
The lesions and their course sound very much like a bacterial skin infection (folliculitis) which is indeed very common and follow the course you describe. Herpes is also in the mix and your negative blood test means only that you have not acquired herpes in the past. It is of little relevance to recent events. Finally, the only other STD which comes to mind is syphilis. Little about what you describe sounds like syphilis and the disease is very, very rare (you probably had a syphilis blood test as well which, unlike the herpes blood test, is more likely to be accurate at the time you were tested)..
Non STD causes (besides folliculitis) include allergic reactions or drug eruptions to any number of chemicals, soaps, vaginal hygiene products, etc which you might have encounter in the course of events.
The sore throats fevers, etc are just as, or more, consistent with some other community acquired virus than an STD.
Hope this helps. As I said, at this juncture, the best thing to do is to wait and see if it comes back, all the while hoping that it does not. EWH
I just want to make clear that when I wrote all STD tests were negative that did not include any cultures. The doctor thought the lesion had healed too much to be successfully cultured, so no culture was done. Also, I was not on any medications or other drugs at the time of the outbreak described above.