If you're not filling your tank, it's a good possibility that you burned your wick, which will give you the burning sensation when you take a draw. This is not a dripper type of tank, it's made so that it holds liquid. You need enough liquid to keep your wick wet. I would change out your heating coil, refill the tank and let it sit for a few minutes to let the liquid soak into your wick and then try vaping it again. Start with a low wattage, vape. If that doesn't give you satisfactory results, increase the wattage/power by just a bit and vape. Repeat until you get just a hint of a burning taste, back down your watts a bit and that should be the sweet spot for that coil and juice.