To be massively struggling?

[sameday2021]

DH out at work 12 hours per day
Homeschooling 2 primary age kids
Trying to work, keep on top of house, not fall into the trap of eating convenience foods...
Kids are too young to go for long walks and moan most of the time even if snacks and scavenger hunts included.

Literally feel like I'm in prison.
Yes, I'm home safe.
But I can't go anywhere, I can't do an online course, or watch a film, or read a book.
All I see is mess, squabbling kids etc

What are you all doing to keep sane? I need some serious help putting a strategy in place.

I thought about power walking 5k every night once DH home?

Perhaps take an afternoon bath while the kids watch a film.

Total envy at the older ladies I saw out walking with each other earlier :(

It's hard right now. Mainly because of the time of the year. I'm seeing it as a challenge that I need to get through and there will be rewards at the end.
My kids are y2 and y5. Our school is doing live lessons this time, that they expect you to attend. The pace is fast. My parents had offered to have my kids one day a week for me, but that would mean we would miss that days work and lessons so don't know what to do? I took a lax approach last time but if we don't do the work this time, especially maths, my kids will be left behind? So I feel like we absolutely have to do it. But they both require my assistance so I don't have a minute to do anything else.
Husband is back at work, from 7am to 6pm, he expects tea on the table when he walks through the door. He doesn't help with ANYTHING in the house or with the kids. Both mine hate going for walks etc when it's cold and wet. But during the warmer months we are outside all the time and we have a large paddling pool etc so its much more bearable then. I just want this nightmare to be over. At night when I'm exhausted, I almost wish I didn't have kids because of how hard it now is (then I feel tremendous guilt) because they are living through this too and I think the kids are having to deal with an awful lot bless them.