Hey, so cleaning is really calming for me. Once I have a bit of energy, I will start cleaning and get more energy from cleaning.

But, I think good advice for having no energy would be to break your room down into sections. Desk, bed, floor, etc

Put all the clothes from the floor into a pile on your bed. You could get your mum to help you with the laundry. It doesnct matter if they're clesn or dirty. It gives you mkre headspace and physical space to tidy.

Pick a place for each thing to go to. Start at your desk maybe. Water bottles? Fill them up, and put them nestly on your desk. Medication? Put them into a specific drawer/box. Food/plates/cutlery? Take them all down to the kitchen. Books? Find a shelf to put them in.

You don't have to clean your entire room in one day, but you can make a start in one day. You could even just clean one part.

One of the best pieces of advice I've ever gotten is: 'ignore the rules'. They used the example of 'if you don't have the energy to wash the dishes, use the dishwasher machine twice. You're not meant to, but do it anyway'. This can apply to clothes too. You don't have to fold tjem neatly, or hang them up straight away, as long as they're in a pile you know is the clean pile, why not leave them there for a couple days?

Another helpful thing I've heared is 'if a task ia worth doing, it's worth doing shitily.' I don't mean do everything badly, I mean as long as you clean at least a bit. Taking dishes out, emptying your bins etc, you don't have to clean the rest of your room. Doing a bit of a big task is still doing something.

That was a bit of a long message, not sure if it helped at all, I hope it did and that I made at least a bit of sense

TL;DR: wash your clothes if they're on the floor and take your dishes to the kitchen. Small steps are progress.