What Causes Painful Bumps On Private Parts?

Sometimes I shave my private are but its these bumps that come and they hurt sometimes very bad. Its been two or three weeks since I shaved and these bumps keep comming and also when I dont shave I still get them. They sometimes bleed and are like small bumps.What could it be?And how do I get rid of the scars they leave? I am not sexually active either Please help me