I know how you feel, but if he is honestly working that much, and you have elected to be the stay-at-home mom, I think you have to face that no one should only do "half" a job. Part of staying at home is taking care of the home...if you were working, he wouldn't have to work as much, and the two of you could more evenly share chores.
That being said, I am a stay-at-home mom, and I know your frustration with him not recognizing how tough it is to care for two children (or more!), but think about how great he'll think you are if you CAN do it all...and trust me, you can.
One hint I've found that I'll share...start from immaculate and do things right away. Have him take the children on his day off, then clean the house from top to bottom, organize, put away...really do it all. Then, when things need to be done or put away, do it as SOON as you can. You know, dishes RIGHT after a meal, dry, and put away, laundry RIGHT into the closet instead of a stack on the chair, toys away after children are in bed (they play better each day if they can start fresh, anyhow).
And as far as cleaning goes, it's so much quicker and relatively effortless if you do it before it "needs" to be done. Seriously, try cleaning your bathroom three days after you've done it, and you'll find it takes about five minutes because it's still "clean"...and it's so easy! So just do it every three days, and it only takes five minutes. I do the same with all my cleaning...and it never becomes "heavy duty" cleaning because it's being kept clean before it gets dirty.
These are things I've just figured out along the way, but then again, my children are older than yours and I've had to time to figure out how to deal with my frustration over it. You will find a way to do it, I promise!
But please, don't take it out on your husband...there are so many people who are not fortunate enough to have a hard working husband who works so hard just so you can stay home...and that is a gift! :)