Can you sustain an erection and satisfy a woman or a man? This is vital info.
The most common rash in the area you describe that looks like what you have is eczema. This is irritated, but not contagious. Treating with a steroid cream like the one you're using helps, but only temporarily.
If you're embarrassed to see a skin doctor, I think you don't need to be. You almost certainly don't have anything sexually-related or contagious, so you have nothing to lose by going and much to gain by getting a proper diagnosis, good counseling,and proper treatment.
Best.
Dr. Rockoff