Sorry to hear that, cancer is scary. I am sure you'll come through just fine.
That's coming up pretty fast. At ten beers a night I think I'd get the assistance of my family physician if you are going to quit drinking, they can give you medication to cushion the withdrawals. You'd be pretty much through the rough parts by the 11th if you quit today, but time is getting short.
Maybe this is an opportunity to take that first step and make a lasting change, though, that'd be pretty cool, huh?
Good luck on the surgery!