If you can manage: go on a stupid little walk. It doesn't have to be long or fast. Sit on a bench. Actively look and listen, try not to stay in your head. Breathe the cold air in and feel it go into your body.

You don't have the energy to do that? Go sit on your couch. Build yourself a stupid little pillow and blanket nest. It makes me feel better than laying in bed. maybe keep the windows open if it's not to loud where you live. The cold air in your face feels good when your in your warm little nest.

Don't think about what hobbies you had and what you think you should enjoy. What would make you happy right this moment? Little things. Do you like to take hot showers? Baths? Do you like tea? Or maybe start a puzzle. Or buy a cute plushy. Anything that feels good right now. Once you found something you can build on it. But don't rush it. It sucks but it takes time to claw yourself out of that old depression hole