Any time you can, try to do whatever you’re doing in the sunshine! If you have a deck/porch/yard start going out there to play on your phone, read, eat lunch out there sometimes for fun, paint nails, make jewelry, drink coffee or tea, write, research. There are so many things that can be done outside, try to start telling yourself there’s no reason to just sit inside on your phone when you could be outside in fresh air.
Whenever I was in a period where it was harder to make myself do things, I always found that even if it felt like a chore to get up and go outside, once I was out there it always felt great. I also love going on walks with or without headphones and just maladaptive daydreaming.
Maybe once you get into a habit of getting out more little by little you’ll find yourself enjoying it and doing it more habitually!