actually the likelyhood for 3 negative tests for herpes is not as rare as you think. Herpes hides itself in the body within your spine, that is why your body cannot find and destroy it, it is incurable. Herpes is quite difficult to find sometimes, hard to test for. It does sound a little like herpes to me, the blisters do, but the shouldnt be there for almost a month! mine went within 5days. What was the medication you took? Also, I am not sure how easy it is to transmit simplex 2, but simplex 1 doesnt viral shred as much and is a lot harder to transmit to a partner. If your ex didnt have an outbreak whilst having sex, or an outbreak not long after then you may be ok, plus it is harder for a man to get it. Either way, it is odd that your tests for all STD's were negative, maybe you should be testing for something else. Good luck with whatever you decide.
You need to go and be seen monday and get a full work up. Not just blood tests for herpes, you need proper evaluation at this point. it would be very unusual for herpes to last this long unchanged so it's likelyto be something else.
grace