Packed up my 510 and trex stuff after 2 weeks. I bought all my juices from Terry. That being said, I love the 510 and trex, but get headaches after using it. I can't deal with that. I started on 12 mg, but felt that was too low, so went to 18. All the stuff I have gotten has been pg/vg. I smoke a pack a day of marlboro ultra lights. Am I using too low/high nicotine, or is it a PG issue and need to switch to VG? I am still smoking the occasional analog, but the headache comes from the ecig. Please help if you can, I want to be off of analogs by the new year, and if I can't figure this out, I am lost!!