Caveat: What do I know -- I have never smoked and never even felt any positive sensation from smoking, so I have no personal experience with smoking. I agree with everyone who is saying DON'T DO IT! Of course! Don't smoke!
But if I'm understanding your question, it is not whether you should take it up (you know you shouldn't), but whether there are strategies to avoid doing so?
From what I'm told, a lot of the times, the urge to smoke is triggered by certain stimuli/situations. So, for instance, did you always smoke before drinking a cup of coffee? Or did you always smoke when you feel stressed? Or when you take a break at work? For some it is that physical link that must be broken: the habit of step outside, bum a cigarette, shoot the breeze... And for others it may be the sensation of release they get, and the trigger is not so much particular locations or environments, but the the emotional feeling they had before they smoked and the emotional feeling they anticipate getting afterwards. So I would say to think carefully about what it was you felt after smoking that was so gratifying. Was it a feeling of relaxation or a a feeling of being wired or energized? Is there some other activity that activates similar pathways that you can try to incorporate instead so that you can essentially retrain the habitual link to focus on a healthier activity?
From what you've written here, it sounds like the trigger for you is the stress of dealing with a chronic illness 24-7. So what I am suggesting may sound a bit unorthodox, but what if you just took a CGM/bolus break for a few days? If you can't actually leave (your wife would probably NOT appreciate that), just ask her to be in charge of all the bolusing and the CGM stuff and just sleep, eat and do your ordinary non-D life stuff. Don't check any devices related to diabetes, and just interact with your son as if he didn't have this disease (super super super hard, I know ...) Maybe you can take on some of the tasks she usually does as a trade if its simply too much for her to manage, or even call in in-laws for a weekend to help out with all the non-D stuff. Lest you think I'm suggesting something one-sided, you can do a swap with her for some other time when she needs the same from you.
I (as you may have noticed) am mildly obsessed with keeping my son's BG in check and don't even mind that most of the time, but I recently went to a conference for four days and didn't check my son's blood sugar and left it to my husband, and I felt like a human for the first time in a long time.
When I went back, I went right back to checking him, obsessing about his numbers and micromanaging everything, etc, but I've definitely noticed the edge has come off. I'm less likely to sweat it when my husband does it differently and while I respond promptly, I recognize that each high and low is not really an emergency (unless, you know, it is :), stupid diabetes!)
Same thing with diabetes camp-- in August we went to a camp and for several days counselors tracked and treated his lows and highs and it was really a turning point in our family life...we went from survival mode to one step up....subsistence mode maybe? We finally felt like a family with diabetes in it, not a group of people whose sole purpose for being together was treating diabetes.
Anyways, what I'm saying is that it sounds like diabetes is the main trigger for this urge to smoke, so putting it in the proper perspective and taking a break as much as possible might help conquer this urge. Being a parent of a t1D SUCKS but in one respect we have a luxury that our little ones don't...we can at least theoretically take a day off from the constant worry and thought of diabetes.
Good luck, it's a hard road and I know you'll figure out the way through!