Bless your heart OP. So sorry you feel so terrible - it's not your fault.
I get it. I think sometimes when you feel like that, you almost go into 'self punishment/self neglect ' mode. So you kind of continuing doing the things that know make you worse because you've stopped 'caring' about your own self care.
It's also very 'rut' like behaviour. So easy to just dig yourself in further.
What I would say, is give yourself a bit of a break from the pressure you're putting yourself under to be perfecting great self care. You're not in a place to achieve 'great self care'. The added pressure will be much worse for your mental health.
Great self care is to be practiced as 'maintenance ' to maintain adequate/good mental health once you're in a better place.
So at the moment, if scrolling is a distraction, just do it ! And forgive yourself. Set a timer. So scroll for 30 mins. When the timer goes off, do a small chore (brush your teeth, comb your hair and out it in a ponytail for example) split tasks into really small manageable chunks between the 'unhealthy' habits.
When I'm feeling in a bad place , I write lists. 'clean teeth' 'put make up on' 'wash children's uniforms' . It just helps to 'achieve' something when you can put that tick in the box.
Don't put yourself under unnecessary pressure at the moment- it won't help. Work on the smallest steps first - then make strategies to get off your phone etc when you're in the 'maintenance ' phase.
Good luck. You're not always going to feel this way, despite the fact you can't see that right now.