What should I do about acne scars?

I got a big acne scar. T_T

It was a large, red pimple, but I was too lazy to go to the dermatologist, so I poked at it at home with extraction tweezers. Now, a line-like scar about 1 centimeter long has formed. It hasn't gone away even after 5 days. T_T

It bled, and it hurt because the acne was squeezed as if my skin were being pinched.