I believe in you more4me..
I have a few cousins who were hardcore junkies… Not just anything either, Crystal Meth AKA Ice.
3 of them were lucky enough to have the help to get off it. One slipped but has since had help again. Unfortunately the other wasn’t so lucky and doesn’t even recognise me anymore. I don’t think he has very long to live if he doesn’t get off it, but he is far beyond help.
Anyway my point is that if you have support, and looking here you have a lot of it, you can do anything. Pick up a hobby. Learn how to do something you’ve always wanted to learn. And when you feel like a ciggy, practise that thing.
Things to do to relieve stress – I have a diary which I write in ONLY when I am stressed (seems to be a lot lately). Write in it, then read what you wrote the next day. You’ll most likely laugh at yourself. AND it takes 2 min+ to write in there so you’ve escaped that craving. You’ll also have something to look back on in years to come and realise how strong you were to quit 
You could always get a friend to chain you to the house too Although that wouldn’t be as fun as learning something new.