I have been vaping for well over 7 hours now. Actually taking a break. But in a few instances I have become light headed. Nothing extreme, just a woo feeling. Like I used to get when I first started analog cigs. Remember those days? I've eatin, I have kept fluids in me. So I'm wondering if I might of just over done it on my starter carts. I don't remember what mg they are but they are labeled high.