Just wanted to check in to see how you were doing? Have you been able to consult a doctor?
It sounds like you suspect that you may have an STD, since you mentioned your encounter. The best thing you can do to put your mind at ease, is to go ahead and see a doctor about some routine STD testing.
I'd also recommend seeing a dermatologist, black spots can be caused by various skin conditions, so it's best to get a doctor to take a look at diagnosis you.