I agree with upping your nic. I vape at 18 mg nic and started on a Nautilus 2, which is really one of the more "true" MTL vapes. I've branched out and will vape at lower resistance at times, but I'm still using that nic, and still in a pretty MTL fashion, I think my highest wattages usually hover around 12 watts, lowest around 6. With that wattage and a MTL tank you need more nic to compensate for less vapor. With that said, I tried DL initially and it didn't work for me at all. But since you have the Nautilus tank, I'd say trying to up your nicotine first. But, as Letitia says, sometimes DL suits someone much more...
Best of luck, glad you are starting up vaping again. I dual used for a couple weeks the first time around but I did *NOT* quit vaping, I would vape right before (and right after) every cigarette, and over time I was able to drop those cigarettes. It wasn't easy and I needed determination and willpower, but my first cigarette-free day, I almost keeled over in shock
Then, detox REALLY started, but I didn't want to go backwards and the nice thing is, it will end.
Anna