Sadly this isn't always the case and I would suggest being prepared for your employer being unsupportive at some point is wise.
I was a carer for my dad when he was put on end of life 10 days into the first Covid lockdown. I was working from home at the time but employer insisted on my going back in even though I was trying to shield to care for him and there was no practical need for me to be physically at school.
I went back after the summer holidays and made it through until half term when I was signed off with stress. Despite knowing what I'd bee going through and the fact that I'd been referred to mental health services for suicidal ideation during the holidays, I was called in on absence procedures within three days of submitting my sick note.
The meeting took place a couple
of weeks later and they offered me the rest of the academic year on unpaid sabbatical and said to think about before the next stage of absence procedures. During that time I received a letter which basically inferred that if I didn't take the unpaid sabbatical, I would be managed out.
On paper I was entitled to 6 months full pay and 6 months at 50%, but obviously wasn't in a position to fight my corner.
I took the unpaid sabbatical, went back at the start of the next academic year after my dad had died. I was basically demoted to office junior in all but name as my responsibilities had all been handed to the person who'd been brought in to cover me.
I'm really sorry you're experiencing this and hope your employer is brilliant, but it does no harm to be prepared for an alternative outcome.
In the meantime, just get signed off for now and take it one step at a time for as long as you can. As you've said, everything is very up in the air at the moment so it's probably only going to cause you more stress to try and look that far ahead.