Husband works. I get that.
So what hours doesn't he work?
You have to carve time out for yourself. Once child in bed get in a bath. Just an hour, hot scented water, book or magazine. H van watch an hour if TV you hate and listen out for any waking up.
The biggest shock having two children was for my H, I could only put one to sleep at a time. But he did it he had to.
3-5 years per child of full on never ending exhaustion. I am just being honest. But you knew all this before having kids.
The other side of this is to enjoy your efforts, when they smile and run up to you that unconditional love that you are just the most super thing in the whole wide world. No one ever will love you just like this.
Can H do swimming and then go to the shop to grabs some small items? Or have a hot drink after to extend their time out of the house?
If you have a safe garden can toddler explore whilst you just chill with a herbal tea keeping a watchful eye but for an hour forget about the other chores just stand/sit in garden, almost meditating, concentrating on breathing finding a calm moment?
You don't have to fill a child's every moment.
Just trying to "find wally" can effecting be a sit down with a picture.
But alone? With a second baby on the way? Yeah not easy or even possible for some/most.