I am completely new to this so I may have messed my atti up. I was using the first flavor i purchased at the store for a few days and it started to give me nasty headaches. So i order some liquids from Mountain Oak Vapors Premium Tennessee E-Liquid - The Best American Made E-Liquid on the market!. I tried to get all of the liquid out when i got the new stuff. After a few days it seems like the taste of the e liquids is not as strong as it used to be. I am wondering if i changed the liquids too many times and now its contaminated. please help