What Causes Itchy Red Lines On Labia?

I Have Red Lines On The Inside Of My labia. They looks Like Cuts But Theyre Not It Hurts Very Bad And Is Extremely Itchy. Im 23 years Old 123 lbs 5'6" Im sexually active and just had a pap smear and came back negative for everything. the itching and lines have been getting more severe everyday and its been about a month.