Sexual Health - is it an STD
You've asked a number of questions which I've repeated below:-
Could it be a fungal infection causing these problems even with what I have noted above?I think very very unlikely - you need to show this to and discuss with a doctor experienced in STD's. I dont think it is an STD but you need to be able to have a full discussion.
Could it be Herpes or Syphilis? No classical sores of either.no
Are there any other (more obscure perhaps) STD's or viruses that could cause this?no - but I repeat my comment as in 1) above
Is it just a skin problem?extremely likely - but see my response of 1 above If so could it be brought on by stress of worry etc. NO
Best regards, Sean