what is this sharp pain in my hip?

[Mojo Jojo]

i have a very severe sharp stabbing pain in my hip joint. it is shooting right down my leg towards the knee. i have had the pain a little less than 12 hours. at first i thought that maybe is was a cramp of some sort and that it would go away but it hasn't... as far as i can remember i didn't hurt my self.. it just started to hurt. i got no sleep last night because the pain was so bad. at one point i couldn't move at all. no matter what i do, stretch it, rest it, sit, stand, lay down, it always hurts sometimes eg while stretching it hurts more. im 18, and it doesn't feel like growing pains so don't give me that! lol i even tried a heat pack but it didn't relieve the pain hardly at all! PLEASE HELP! it hurts so bad! and i can hardly walk!! do i need to see a doctor? what is it? what should i do to relieve pain?? PLEASE HELP ME!! thank you sooo much! x