Some of the responses to the OP in this thread are outright rude.. this forum used to be a friendly place, where people helped each other out with out belittling one another. Let's keep in mind, vaping is still new to a lot of people. Juice doesn't come with instruction booklets, although my bottle of nic salt juice does have a warning label not to be used in sub ohm devices.
Let's remember, not everybody understands coil resistance and what that means. Not everybody has a local vape shop, where the staff can properly inform them. OP hopefully you've figured out that your juice is way too strong for the type of tank and coil you're using.
Most people gravitate to 3mg juice when using a sub-ohm device. As a 2 PAD smoker, 6mg is my sweetspot. 3mg was sucking on the vape all day long. Sub-ohm devices get way hotter, and evaporate more liquid in a single pull than you would with standard resistance or even low resistance coils above 1 ohm.
What wattage you vape at, highly depends on coil resistance, and type of coil. dual or triple coils at .2 ohms, will require more wattage than a single coil at .2 ohms, where with standard resistance or even low resistance coils above 1 ohm, you likely wont exceed 10 watts, before you risk ruining your coil/wicking material.
Before anybody was sub-ohming I was using 24mg freebase nic juice in a standard 3 ohm 510 atomizer and the first hit gave me a headrush. Thats when i knew it could replace smoking for me. OP your juice is intended for a higher resistance coil, hence you're getting choked out by it. Lower resistance = more vapor, more juice consumed, more exposure to nicotine.