If you don’t have prior experience with Linux, I’d advise making the switch before the end of win10 support. I made the switch a couple of months ago with no experience in Linux, and while it wasn’t a horrible experience it also wasn’t the easiest thing to do. Having the safety net of a Windows partition was really useful during the month or two as I got used to Linux, which I wouldn’t have wanted to do with Windows not in support anymore.

Having quit this year (after a long time of cutting down/vaping etc) I think my main advice to you will be this:

If you relapse it isn’t the end of the world, it’s just a bump in the road. Don’t be too hard on yourself, it’s not easy.

Also, keep a pack of smokes or a vape or snus or whatever you use on you for a week or so after you stop using them, so when you feel your pockets you don’t panic when you’re missing something, which will set off the response to “I need nicotine”

Good luck!