Hi DM,
or should I call you Superwoman LOL. You have an overwhelming load that you definately need help with. Reach gave some great advice. But Blue Cloud also had a good point, that it has to be done firmly and gently so you don't appear like you're just a big crab. Children combined with a full work load can put a big strain on a marriage. You certainly should be delegating chores.
I would recommend, since you have inlaws in the house, that you and your husband go on a date night so you can re-connect. When you are out, don't talk about any thing stressfull, just enjoy yourselves. Best of luck, slow down and take time for you.