I had bumps that formed near my genitals that formed a dark center and eventually shrunk in height and turned all black (or purple). the pain is bad.

Herpes zoster?: Need more details, but sounds consistent with herpes zoster (shingles). This is more likely if the rash is strictly one sided, i.e. few if any bumps on other side of body midline; if initial bumps were red then blister-like before turning dark; and if happening in a few days. Shingles needs prompt Rx to prevent long term pain, so see MD ASAP, urgent care today if your doc isn't available. Gd luck!