I am about to begin working out again after a 2 week stint from surgery.

I want to lose fat and regain some of my lost muscle so I'm going to start doing cardio @ 75% of my MHR, but I'm not sure if I can get away with whey, creatine, dextrose shake made of skim milk 3x a week? It sounds too tasty and good to be true.

Many utilize whey/dextrose/WATER as a post-workout drink after WEIGHTS. Not sure if you were thinking of drinking this after cardio, but DON'T.

Also, nix the milk, it slows digestion and you don't want that PWO at all.
As well, milk's carbs are all sugar, and you have sugar already in the form of pure dextrose.

~SC~