I always seem to be late to the discussions and now OP says she's hidden the chat so probably won't see the response to this but I was going to say, it sounds like you do an awful lot for the family.
I don't think that having a busy day with multiple things to do now and again constitute some sort of scheduling failure.
And it does sound like you are stepping up all the time because your husband is stepping back. And it's so easy to say well, make him do more, and you say, he won't. So the kids will suffer. They won't end up going to their activities, they won't end up going to their parties, because he won't. And why did you have another kid with him if he's like this? Because he wasn't like that when you had another kid with them years ago. But now he is.
Yes this is pointing to a husband problem, but you didn't need anybody's confirmation, you already knew that. The thing is, You feel like this is totally unfair that you have to do everything and he can do things like take the morning off, sleep in late, take a nap, and you're running around like crazy making sure everything gets done. And no it's not fair. And then if you try to take some me time, you feel like the kids won't be properly supervised, and that's not fair. Because Daddy being home isn't helping out, isn't babysitting, it's parenting.
They don't get to "help" for half an hour or an hour out of a 24-hour day 7 days a week 365 days a year And that's considered to be their fair share of the parenting.
Sorry, OP. I hope that you get a little more sleep tonight and possibly that your husband steps up a bit more to help out. It's not fair.