You arne’t supposed to have anything sweet, that’s the point. Sugar is a bit like nicotine, your brain becomes addicted to it. You feel rough at first then it’s ok. You start realising that things like green beans, broccoli and carrots are sweet, and you relish them.
Don’t try and mimic the stuff you’re cutting out. You’ll end up making all sorts of contrived things and they won’t be as good. Just relish the things you can have and get used to cooking to get the best out of them.
With regards exercise you do need simple carbs if you exercise – I found that for the training I do I seem to need a bit more than prescribed to allow me to train, and I see better weight loss that way too.
If you really crave something sweet then there’s a chance you have run your carb stores low – this may or may not be desirable depending on your goals.