Hey there, I'm new here as well. As others have said before me, don't worry about having a cigarette every now and then -- as long as the quantity is decreasing over time, you're golden and well on your way to being completely tobacco-free as far as I'm concerned.
All you need is to find the setup / juice that is right for you. I personally went through my share of crap batteries / juices, to the point where I thought vaping wasn't going to cut it as a serious alternative... then I came across the setup and liquid vendor(s) I use today (and have been for the last year of my life, which has also not-so-coincidentally been tobacco-free).
Cheers!