i have no clue whats wrong with me..somoeone help!!

Hi im 15 years old and about 3 weeks ago these strange things started to happen first,i got a veyr very bad headache for about 4 days i never have headaches so my mom took me to the er meanwhile during the headaches i noticed my arms,legs,neck jsut my whole body kept jerking but it didnt really worry me the dr. in the ER said its just a migrane (migraine) and said get some rest and sent me home about 2 days later the headache went away but the jerking twithing got worse..alone with a stiff neck..i couldnt stand it it seems like my whole body feels like it throwing itslef if u no what i mean but the bad thing is..no one else seems to see it and when i jerk i usually try move with it to make it not noticable so i begged my mom to take me to the dr.again so she did he said that i could just be a twitch and that if it didnt go away in a few days call the neuro. so i didnt go away and i did ..so he did a exam and he said theres no reason to think anythings wrong but hes sending me for a eeg and a cat scan but that id have to wait a few weeks..sinse then the jerking tiwtching..im not sure how to describe it has not stopped its all day everyday i still have a stiff neck and now i have dizzyness i am very very tired i feel like im dieing and all i can think is that i have als or ms or somehting very very bad..and that a cat scan is not going to show something like that my mom sais that if the test showing nothing im not going to see anyone else..im so misserable and dont no what else to do..my family thinks im makeing this up...i cant stand the jerking anymore..can someone tell me what this could be??