?????? pain?????? please hel is it hernia???? what can it be?????? please read!!!!!!!!?

hi, here my problem, i believe this problem started since i masturbated. when i go on roller coasters and i go down really fast i just get like a cramp on my . you know when you get erected you then touch your until you go all the way down and almost get to the , that when i feel the cramp from. this only happens like if i jump off the stairs or go down the roller coasters, in no other times does this pain come to me. what can it be. i mean the pain goes away quick goes away in about 20 seconds but it hurts quite a bit and gets frustrating when trying to enjoy roller coasters. what can it be, hernia, or what, will this get fixed if i stop masturbating. im going to stop anyways but i mean will it even work??