Also, I wanted to add... I had a terrible time with those last few cigs. I really did. I ended up deciding to try WTA juice, which is e-juice made with tobacco that actually has some tobacco alkaloids in it (regular NET tobacco has tobacco flavor, but tends not to have the alkaloids). Because I was detoxing so hard, I decided I would use them transiently, and I started out with a tiny squirt of them when I refilled my tank. I don't use them consistently any more, but I do have a tank with some in them that I carry in case I have Stressful Situations afoot, like going to an evening concert for the first time, vaping (the first time I did that, I fell off the vaping wagon-- hard-- the first concert I went to, I mean, 2nd was fine, LOL).
But, if I'm going to be doing something stressful, I find them useful, and they were easy to taper off of (unlike smoking) and I can still use them on occasion and have no desire to continue using them. They don't work for everyone, but you can get them from either Aroma Ejuice or Mother's Milk, they are pricy is the only thing, but I did find they reduced my desire to chew through steel by about 3 p.m. every day. They don't work for everyone, and I would DEFINITELY try upping your nic first and seeing how you do, but depending on how it goes, that may be something worth trying. I didn't want to use them forever, and I'm glad I don't (mainly for cost, I was not supremely worried about my health as no combustion is the main thing that e-cigs offer healthwise, and that is true for WTA liquid as well) but I was really happy to have them when I needed them, and I usually suggest them (if dual users have tried every other option and still finding it hard/impossible).
They're certainly not *required* and I was a pretty heavy duty smoker and had a LOT of detoxing to do, and it was far easier to taper my WTA use than my cigarettes, generally. It's just a thought, at this point but I thought I'd mention it. I bought the wholesale, unflavored, and they have the faintest HINT of tobacco flavor that just blends away for the most part once you add other flavors. NET juice made me think of it, so hey, I'm posting it.
If you wind up wanting to try some, I could probably send some, like a small amount 3 or 4 mls so you could try them, before attempting to purchase any, given it's Oz and all.... Just give me a heads up if you are ever interested, but I'd say with upping your nic, you may not need them at all.... but if you ever feel like you do, shoot me a PM. I'm fond of Oz (my family is from there and I lived in Sydney in middle school) always happy to help a fellow Oz (though I don't sound like one anymore, been here too long, LOL).
Keep on hanging in there, though.

You may do just fabulously on 18 nic and that may be the final push you need....
Anna