You're not a heavy smoker so honestly just quit before you hit that pack a day mark, because after it becomes difficult.
But... at the risk of making enemies here: there is no reason it should inhibit your diving.
Should you stop? Yes. But there is no reason it should or would inhibit your goal of reaching 100 meters.
The main issue into getting to 100 meters is money, not your smoking.
Doing a zero to hero course is definitely possible , but realistically it's not something you can do within a year or so after diving.
Purely because of the bulk of diving you have to do to get ready for the course.
Smoking does put you at a higher risk: higher blood pressure, narrowed blood vessels, less physical condition -> more chance at getting a decompression accident or a health issue under water. I know plenty of smokers who dive.
It's just as with any activity, smoking makes it more risky. But it won't inhibit you from doing the activity itself.
if you want longevity from your diving or anything in life, smoking cannot be a part of it, simple as that.
I used to be a similar 2 pack a week kinda guy, then my job got really stressful and before I knew it, I was smoking 5 cigarettes on my drive to work 2 during my 15 minute break and then another 10-15 in the evening.
I quit smoking for diving, but I have rebounded once or twice and it's very simple : as soon as I start again, I get tired faster, out of breath faster and you're putting yourself at unnecessary extra deco risk, so if you want to take diving 'seriously' you should probably quit, but if you smoke, will you die during diving? Nope.
I know plenty of guys who have done 1000-2000+ dives while chain smoking. I also know plenty of these guys have had deco accidents while following their computers on conservative settings to the T. Most of them also dive less and less as they age because of health issues. Are they smoking related? I can't prove that. But fact is, it's deteriorating your health at an extra speed and you're increasing your risks in an already risky sport (especially when you're going deeper with helium mixes where flushing your system becomes really important.)