The cacao content is what's good for you. Sugar free milk chocolate doesn't necessarily contain a high cacao content, and likely contains artificial sweeteners, which is why they're usually avoided by those of us who try to avoid artificial ingredients. Your cocoa butter is probably separated, natural oils will do that. You might want to refrigerate it and stir it up. Cocoa butter is NOT cacao, don't confuse the two.
F 28/5'4/100 lbs
"I'm not a psychopath, I'm a high-functioning sociopath; do your research."