Put on a huge amount of weight in a few days. Panic

I was wondering if I was eating enough calories before but I was still loosing weight so didn't worry about it too much.

Can you or someone explain what glucose stores are to me?

Do you really want to only lose weight, no matter what it is?
Or do you want to only lose fat?
You can end up skinny fat as many do, thin muffin top squeezing out of pants whenever you bend, then arms flapping in the breeze, ect.

Eat too little for your level of activity, have the wrong exercise, and not eat enough protein, and you'll lose muscle mass, lowering your metabolism, and under-eating also lowers metabolism more than even that would cause. Bad combo for being able to continue losing well or go into maintenance later.

Just because you can pound a finish nail in with a sledgehammer doesn't mean it's the best way to do it.

Glucose stores are limited, around 400-450 calories worth in your liver, keeps the blood sugar where your body wants it, always topped off after a meal with any carbs in it, if not, excess amino acids converted to it. If none, muscle is broken down to convert to it.
Stores in your muscles range from 500-2000 depending on your exercise type and how fit you are and how much muscle you got. 1 gram of glucose stores with 2.7 g of water, meaning 500 cal worth weighs 1 lb. Those stores are only usable by the muscle they are in, can't be put in the bloodstream for use elsewhere. Once gone, liver stores used by the muscle. If that's too low, get ready for muscle breakdown to convert for usage. (fat is used as energy this entire time too, low intensity about 50% fat, high intensity can be none).

That's weight that increases your metabolism too, so desired weight. Besides fluctuating weight.

But if one decent unusual day of carbs of 500 excess of what is needed, and you weight goes up 1 lb, your stores were low already. Bad state to be in, missing out on extra Lean Body Mass that increases metabolism. Plus needed energy stores.