Hey there...congrats on the good news. I know how scared you can get when you smoke and you know what that can do. But remember...it doesn't always do that,

So for now, you are lucky!
I would advise to continue to get regular checkups with your dentist and go from there.
I would stop worrying yourself though. You don't need to stop checking, checking is ok...to an extent.
Also another good thing to remember....if you get a sore in your mouth...wait it out a bit. If it lasts 2 - 4 weeks, then talk with your dentist about it. If you aren't satisfied with their answer, try to see an ent or oral surgeon for a different opinion.
I was toyed with for 5 months before they finally did the biopsy and discovered it was cancer. They kept telling me I was too young and just chewing on my tongue when I slept due to stress. Granted...neither my normal dentist nor the first oral surgeon had ever had much dealings with cancer in such a young patient, but still...no excuse!
Cancer can be hard to detect, so just keep your eyes open and keep getting normal checkups!
And thanks for your years of service. It has to be hard to go through what you did and then try to readjust to "normal" life. I worked at a Vets "nursing" home, and many of them had PTSD or drinking/drug problems.
I would like to congratulate you on your sobriety and you ability to stay away from dip and smokes. It's a hard thing to kick, but hopefully this "scare" will help you stay away for good. I know when my sore first showed up on my tongue, that was my last cig and will never go back! So keep up the great work!