Best of luck, Goq. You can do it! One small change that I made that has been a huge help was switching from soda to seltzer. I always liked the taste of Diet Coke better than regular Coke anyway, but someone pointed out that Diet Coke still has all sorts of stuff that is bad for you – high fructose corn syrup (not at Pesach, I know), chemicals, and whatever makes it brown! Seltzer doesn’t have all that stuff. It’s definitely a different taste, but it could be an easier transition if the carbonation is something you’ll miss. Also, watch out for flavored “sparkling water” – they add artificial sweeteners, which can still cause cravings.
Real sugar is always better than artificial, but still best in small doses. Fruit naturally has a high sugar content, and someone told me that pineapple has the highest.
Go slow – one small change at a time will make it a lot more likely to become permanent. Good luck!!