Yes, asking about self care is a vitally important question
Do you know how many people I see sliding or have slid into depression and burnout???
Almost EVERYONE over the last year (therapist)
And there is ALWAYS something you can do - you get allocated the same 24 hours in the day as everyone else
If you think there is NOTHING you can do it might mean you're gripping on with your last fingernail as you're now not able to see a way out 🤷♀️
So.... cleaning less/buying ready meals/allocating chores/batch cooking/sharing lifts
And a gazillion other tiny things make a difference when there is very little time
Even taking 10 minutes to meditate/listen to a podcast is a good start as you are then saying to yourself out loud that you are doing this- acknowledging that this time is for you is a really important part of it
You have to value yourself, no other fucker is going to do it 
It's really 'do self care' or end up crying at nothing, completely overwhelmed and unable to stop your thoughts racing during the night...