Dude your energy comes from fats , that's the point in cutting carbs, you want to burn fat for energy instead of carbs
If your going basically no carb then that's going on a ketogenic diet. Your body will burn fat for energy and then that will result in the liver producing ketone bodies , these ketones will then fuel your brain and cognitive functions being you will have no glucose to fuel your brain.
This transition takes a week or so, so you'll be low energy until your body adapts.
Keep in my you'll still need to be in a calorie deficit for this to work for cutting . If you eat too many calories and too much protein your body will just convert that to glucose and spike insulin and store xtra calories as fat
also don't go too lean all the time on your protein , you'll need some fats in your diet . your body will not be able to burn enough of its own fat for all its energy demands, and so will need dietary fats as well (keep in mind that dietary fats are an essential nutrient and needed for survival and health). throw in some avocados , olive oil, etc.
I would not bother with deca or dbol on a keto diet cut . A testosterone only or a test base with primobolan or masteron could work well