Moles keep showing up!?

I am 18 and I have 13 moles that have showed up while growing up... When I was 14 I had these pimples on my shoulders so I would pop them and the next day they would be hard as a rock so I would think they would go away no they stay and after the years went on they started getting huger and more little ones would pop up and grow to the same size.. Now they are start to look deformed not round like they were... Some times the itch so bad and if I would scratch them a little they would start bleeding... Well now that I am older I am noticing more and more showing up on my back and arms they start out very small like a pimple then grow more and more... What could this be? I have looked up skin cancer and the ABCDE and I had all of that besides the color.. The color only changes some times from a purple to pink to tan almost the same color as my skin...