It’s hard to quit immediately, the way I’ve seen my friends do it is to stop slowly and distract yourself with other things.
Fortunately, my friend has a partner so he distracted his addiction with her instead. He feels bad when he smokes near her or even brings it up and she also keeps him in check.
Not sure about your situation but maybe be more open towards your partner? They may be able to help.
You can also apply this concept with close friends and 100% family.