When I was in the process of fat-adaptation I had longings for chocolate milk - and I experimented with sweetening my very bitter organic cocoa powder with Stevia, thinking they were both plants and might synergize (it was awful, because 12 drops of Stevia for one drink is way too much for the system - and made me feel weird). So, I gave up on that and instead went the route of working with keto-friendly natural sweeteners in smoothies and ice cream. However, for your goal to avoid such things, you might try making “chocolate mush” - good cocoa powder added to extra virgin coconut oil, or coconut butter with a little salt - and mixed a lot with a spoon (if you add some avocado it’ll get pudding-like). It’ll still have that cocoa bitterness hint, but the coconut oil does have a lovely natural sweetness that helps.
Later on, once you’re 100% fat-adapted and you can also take 1/4 of a ripe banana and mash it with some cocoa (yes, that’ll be fructose + minerals and not much fiber, but makes a good low carb dessert for special occasions - if one can keep little banana chunks frozen in the freezer and have them not be triggers for bingeing etc).
Full detox and rehab from sugar is a noble and worthy effort - as is keeping LCHF/keto sustainable for you for the long term - and only you can figure that out, with the help of science!
The classic LCHF/keto books Protein Power (by the Drs. Eades) and The Art & Science of Low Carbohydrate Living do have dessert recipes and allow for treats within carb limits - once folks have made it through the very sensitive first weeks/months.