Hi everyone. I have been getting headaches lately when I vape. They are painful headaches in the back of my head down near my neck. It happens when I spend a lot of time running the battery down... I am wondering if this may be caused by the nicotine of if its from the PG. I don't have any 0 nicotine stuff to try so perhaps I should order some and see if that gives me a headache. any other suggestions? What about the non PG based liquid? the vegatable stuff.. any suggestions where to get it?