Whats wrong with me?! please help!!?

hey guys, something really scary and freaky is going on with me, i dont know what it is, it could be paranormal or internal but what ever it is it is getting worse every night. i wake up really late at night or really early in the morning to my left leg feeling like someones cutting it off and stabbing it and burning it all at once. almost ever other night. it hurts so bad but its getting worse and worse! this morning around 6is or 7 i woke up from a deep sleep of it hurting soo bad i couldnt move it or move myself and i was screaming like a teenager from a horror movie. im 15 (btw) it sounded like a teenager getting brutally murdered thats how bad it hurt and how loud i was screaming from the agony. i cant describe the pain. it lasts about 7-15 seconds. keep in mind this was the worst one but not the only one. this was about the 4th time in a week period. but in the day time i can walk on it and run on it all all the normal stuff! whats happening? it looks juust like my other leg. its getting so bad. please help