Help please! I'm in pain!

So, one of my inner lips is longer than the other and it's chafing against my underwear/legs. I can't walk, let alone for b-ball practice. I'm currently staying at home because it hurts so much. I asked my mom what to do and she didn't know what I was talking about (I didn't know what it was called and I'm not too comfortable talking about these kind of things with anyone). So I talked to my Dad, who has a Physical​ Education Major. He understood where I was talking about, but not really what the problem was. He suggested using a pad, but I knew it wouldn't work. I I know my own body (sort of. WHY PUBERTY!), and I knew nothing he was suggesting would work. I don't know what to do. Leave any thoughts you have.

(Picture is not posted because that would be a nude)