All just habits, theyre changeable. Takes time but doable. Best off try giving up one thing at a time. If ya go in with all guns blazing you'll be probably be miserable about it.
You like numbers so get a Fatbit or some other tracker and the Myfitness pal app. Log everything you eat + exercise done into the app. The app gives you numbers i.e calories saved since day 1 so you can see a numerical value for your efforts. You could even throw your gambling hobby into it by having a wager with someone on how much weight you lose in a given time but youd have to be reasonable about it. As for the nosebag end of it. I Know this is stating the bleeding obvious here but If you make all your own grub thats usually healthier than anything out of a packet.
Thats me advice.