Same, I'm also almost 19 months in, after so many tries.
How did you do it?
Turns out what I needed wasn't an iron will but to understand why I smoked. I tracked every cigarette for two weeks, writing down the time and the reason - boredom, a context switch ("I just arrived at the office, now I need to get ready"), anxiety, needed a break...
Once I had that, I could start identifying the reasons for my cravings more easily, which in turn made it easier to switch to a healthier alternative, knowing the craving would pass.
Another two weeks later, I had already cut down my consumption from like 20 to 5 cigarettes a day, which felt wildly empowering. At that point, quitting entirely felt doable, so I did. That feeling made me excited to quit.
I mean, it was still not a walk in the park, but motivation was so much higher than before. I still used nicotine spray for a while to help with the worst cravings.
Right, kids change things. My father used to smoke and the memory of both the visuals and the smell are so vivid, I didn't want my kids to remember me like that. Good on you!