Once when I got a sweet tooth urge I nuked a chunk of cream cheese in the microwave for a few seconds and then added splenda and mixed it together. Not very filling but definitely sweet.
Another thing I've done is 1/2 cup water, a tablespoon of unsweetened cocoa powder, a pack or 2 of splenda, and 2 tbsp heavy cream in the microwave and mixed to make hot chocolate. I put some almond extract in mine too but you could skip that, I'm not sure about the carb/sugar count.

I had no idea cool whip wasn't allowed. Fatkir I will certainly try the HWC, I keep it on hand
Thanks for the suggestion!