Haven't had a girlfriend since high school?

and I turned 21 not too long ago. Did I peak in high school or something? I have hooked up with only 2 girls outside of high school too. I have some acne scars which are visible and ugly looking under direct lighting.but in the dark I feel more confident. I don't approach women much because of this. All the girls I have been with have made the first move on me.I want to change this, what can I do better?