15 years ago, I quit a 20-year smoking habit.
I had to rearrange my physical space to support my quitting efforts. I moved side tables that used to hold the ashtray to the other side of my body so my hand would relearn quickly it had nothing to reach for. My cocktail table held a looooong oblong flower arrangement (no roomfor an ashtray which was visiallyout of pplace anyway). Likewise, I moved my computer to the other side of the room and the other side of the table to do the same thing. Look at your physical space to see where and how you can short-circuit old physical responses and movements associated with smoking.
I drank no beer/alcohol for 6 months, because drinking and smoking literally go hand-in-hand.
I switched to tea from coffee half the times I would have coffee for the same reason. (Back then, though, there were frwer smoking restrictions/prohibitions in restaurants and public buildings.) But it did help a lot - I could have the rituals of a hot beverage without the usual "prompt" of a cigarette to go with it.
I was driven crazy by the smell lingering in my clothing, drapes, furniture, carpeting - anythign fabric, natural fiber or otherwise. I spent a chunk of change getting the smell out with dry cleaning, professional steam cleaning and lots of loads of laundry. Some items still retained the smell and had to be tossed. I got rid of clothing that I typically wore when I went out with groups where I'd typically smoke all evening. (I replaced the discarded "social smoking" clothing with new clothes, and that was surprisingly one of the most powerful "assists.") Fabrics hold smells and covering up the old smells with neutralizing or deoderant-type products WILL NOT WORK- they smell instead like "ocean breeze cigarette smoke" or "country floral cigarette smoke." Since I never smoked while I sewed, I reinforced the no smoking while sewing new drapes, accent pillows, clothing, etc.; I used up lots of my fabric stash, got ahead of the Christmas gift curve with lots of homemade items, and felt amazing actually making something instead of smoking. The "high production" was a terrific reinforcement of accomplishment - everything I sewed underscored all the packs and cartons of cigarettes I was leaving behind forever, and it seemed to put MILES between me and them.
I went to outdoor places where smoking was not permitted or encouraged or easy- parks, beaches, like that. I also started walking more around the neighborhood, parking farther from the entrances of stores, doing things like that to get my lungs and physical stamina back to working order. I found I enjoyed this walking and the whole time it never occurred to me to smoke - smoking and walking aren't a good match anyway! I am not talking about starting any marathon training - just take a walk around the neighborhood and focus your attention on noticing what you might not otherwise - keeps your mind off your old habit and gets you to reconnect with your surroundings otherwise.
One last thing: in my whole 55-year life, I have NEVER met anyone who ever regretted quitting smoking - and every person I have met who quit and resumed the habit has, without exception, regretted it.
HANG IN THERE AND BEST OF LUCK!