hello,,im 35 years old male,i v been smoking pot for last 8 years and finally decided to quit,,i had many attempts but as many times i relapse!because i start to experience terrible headaches!so i had to smoke in order to get pain free....pain killers like Advil,Motrin didn't work,,right now iv made another effort and its been 10 days but my headaches wont go away!!my question -is headache common withdrawal symptom?how long will i have it ?please help,,i really don't want to go back to smoking!! :-(