Congrats on opening your eyes a bit to what you were doing to yourself. That's the first step. All the above is 100%, dead on good stuff. Take it all to heart. But please allow me to change the course of discussion for a second.
Health issues are an important motivator for quitting. No doubt. But I'd like you to consider another issue, which is like the elephant in the room. Consider it carefully: You are seriously struggling with not using a product, and this is just after a seriously disturbing doctor's visit? Again, the health angle is important....but you have an equally serious issue of CONTROL. You have given control of your life to a leaf and it's marketers. Literally. I'll bet you don't even understand the extent to which dipping and/or coordinating your next dip literally trumps all other aspects of your life. Hell, just re-read your opening post with a view toward the amount of control you have given nicotine - even in the face of cancer. Does THAT not scare you about as much as cancer? I say this because I was not smart enough for "health" issues to motivate me to quit. I had scares, and many of those "OMG, maybe I just pushed it too far and got the big C 'cause there's a sore in my mouth" days. But those scares always ended with the sore going away and me laughing at myself for being so paranoid...and continued slavery.
No, what got me to no-shit hit the bottom and act was the realization that this nicotine CONTROLLED ME. And and anyone gets control of me, it's my wife (and she's trying). Nic told me when to shit. It told me what route to take to work. I told me how to pack. It told me to keep all important conversations short (so I could go dip). Etc. Etc.
You're in a scary time. But in a cold, logical, clinical sense....what is done is done. The question now...the decision to plan for now...may be this: If this turns out to be a cold sore or bit lip or something...what then? You gonna figure out some "safer" way to use nic? You gonna chuckle and promise yourself to only dip on Tuesdays or something? You gonna find a more convenient way (like ecigs) to give up control of you life? What if a cancer cure is found? Don't count on it, but what if vaping turns out to legitimately not be a cancer risk? What then? Are you gonna celebrate your heath by giving control back to nicotine, just in a different form?
UST and their ilk want you health and hooked. UST and other companies don't what you to die of cancer...they want you to have loooooooong healthy life. The more healthy you are, and the more nic required to kill withdrawal symptoms, the better.
Let the health issue motivate you for now. Maybe always let it motivate you. But always keep in the back of your mind that using nicotine is voluntary servitude. Do you want to be nic's bitch? I didn't think so.
Quit on brother. Thanks for letting me rant in your intro!