very swollen labia

Please help girls!! 
Just like 10-15minutes ago me and my boyfriend were fooling around when I started to notice some sort of uncomfortable feeling down there we stopped and I noticed that my right side labia has swollen up like a balloon!!! 
I am freaking out, it is starting to hurt a little bit when it's touched and the swelling is causing the skin to stretch therefore also causing some uncomfortableness. 
Please does anyone know how to help???