Just want to say I just started vaping and found this forum to be a great resource of information! Ive read other threads about the subject but none really seem to point to one reason and most are a couple years old and are closed for posting. One thread seemed to point to cigarette withdrawal but thios can't be the case with me since I've been smoking analogs (although it's been less, ive gone all day at work before e-cigarettes without smoking and never had any ill effects). The feeling also seems to be a direct result of the vaping. I'll feel fine in the morning until the first time I vape. Basically I want to know if it's related to nicotine or maybe the PG/VG Ratio. I am currently using 11mg carts from vapor4life which are to my understanding 80pg/20vg. I ordered some blank carts and new juice in 50/50 with 8mg nicotine. I'm just trying to get an idea of what has worked for others without having but buy $50 worth of juice and throwing 75% of it away.