So you believe you know who is, you think, doing some sort of magic, possibly through a psychic, to force you to quit smoking.
I'm also a bit lost on whether you want to quit yourself, but that is outside the scope of your request. However, I will touch on that again soon.
If you believe something like that is going on, you need to look into shielding and possibly warding. There are many good methods out there so I will not go down such a long path here. That said, many are easy enough for someone new to do with a singular focus. If you ask, I can list a method or three larer this evening in this thread for you. But I digress.
Cleansing or banishing may be another good option before shielding, especially if it helps your mindset on the matter.
No matter what, though, the only person who can choose to change something about yourself is you. You choose the steps you walk. Some magic sent your way may possibly influence some thought, but you make your own decisions.