Until you quit fighting with yourself about it, it certainly seems like it.
Seriously.
Once you've stopped using nicotine quitting smoking is about the same degree of difficulty as quitting thumb sucking or getting out of diapers.
Yes it takes time. Yes you have to change your thinking but, Yes it is very possible.
Still sucking your thumb? Still smoking?
If you've unlearned one, you can unlearn the other.