What can I do to satisfy my sweet tooth without using sugar substitute?

You can get a bag of frozen raspberries or freeze some grapes and snack on them when you feel munchy. They are pretty yummy. :) Also, I read somewhere that your body will mistake thirst or tiredness for wanting sweets. So when you get a craving, have a glass of water and a 5 minute nap first (if possible!) , then you can eat if you're still hungry.

Your idea of taking a nap sounds interesting. I'm going to have to try that!