diet self sabotage when starting to make progress?

Ok I know it sounds really stupid but as soon as I start seeing progress on the scales it seems I subconsciously start sabotaging myself. In regards to my diet. I end up going back to eating sweets and processed ****...mainly just chocolate and nutella =[

and then I get very angry and depressed. I don't know why this happens. I'm one of those people who it's either all or nothing. I can't just have one piece of chocolate. As soon as I have one sweet thing I crave more and I can't control myself. So as hard as it is to not give in if I do that I'm good. But as soon as I do have that one sweet thing I'm back in a downwards spiral of eating sweets again and it will continue for days until I can manage a day with 100% clean eating.

Does anything like this happen to anyone else?