I had a similar problem and it lasted quite a long time.(3 months) I had only had sex with one girl and she had only been with me. I decided to try the yeast infection cream that women use, It's uncommon for men to show symptoms of a yeast infection but that is what I believe this is. in order to get better I had to apply the cream a few times daily for between 2 weeks and a month during that time I would limit any masturbation and sex, if you can't handle it, make sure to rinse your penis thoroughly afterwards DRY and apply the cream. (yeast thrives in an un treated damp environment so it is something to avoid)
this will help and eventually the problem should go away. make sure that you keep an eye out for the symptoms starting again and catch it early.
I had a similar problem too. I started using a penis health creme and it really helped me out a lot. A creme that contains Vitamin E will work wonders for your skin down there. Good luck.