im new to this product but ive followed all instructions when using it, i recieved this item about 5 days ago and now both of the coils are burnt (gives me itchy throat when inhaling, low vapor) i expected this product to finally last me weeks after failing countless times with other products. i use 18mg strong menthol (subzero) , 1.8ohm, 3.7v on my aspire vv 1600mah. i have no idea why this is happening since people have said amazing things about it and used it on way higher voltage without a problem. please give me some suggestions