penis pain

Im 24 years old and have had many sexual partners. But around two years ago I went home with a girl, from a bar and had unprotective sex. Then, around a week later I started to get red bumps on my legs, which hurt and a week or two later, the bumps were all over and itching. They moved to my penis and now, two years later I still have the pain.My symptoms of the penis are itching, redness,pain on skin and when peeing, little red bumps, sex is uncomfortable and after sex pain is worst and skin is cut all over.  I have seen many doctors and they have tested me for STD, with no signs, have also have tryed many creams for fugis and bacterial, with no help.  Also antibiotics make the problem worst. PLEASE HELP, YOUR MY LAST OPTION.   THANKS