Your family/Husband needs to help you.
And if not, you may need to hire a Nanny or something.
You can't do this/manage this, by yourself.
And you need to tell your kids, Mommy needs help.
They need, to know.
When you are not feeling well.
Tell them "The Doctor says Mommy needs to rest...." or something.
This is not the same: but when I was pregnant with my 2nd child... and my Asthma acted up my whole pregnancy with that pregnancy. My Asthma was flaring up a lot, and I had a hard time doing anything... I told my daughter who was only 3 at the time, that "Mommy needs help.... my Asthma is bothering me, I cannot run around.... " etc.
And she understood.
I didn't 'burden' her with it, BUT she knew.... Mommy's energy level was not, at the norm. And that, I could not, run around etc. And she was very.... adjusted to it. I told her "The Doctor said I need to rest sometimes.... " and she understood. I told her I need to take care of my body too. And she understood.
She understood.
And I also told her, what my inhaler was for, and where to get it, if I needed it etc. She understood.
I didn't tell her "I'm in pain..." I just explained to her, that Mommy has a health concern, it is called Asthma, sometimes I have a hard time breathing, but I have medicine, and I need to rest etc." And she understood.
You need to explain to your children.
You need your Husband to help you somehow.
And if you have family in your town, they can pitch in.
Or, you need to hire some Nanny or something, to help you.