Whether or not it's "normal" isn't the questions, it's whether or not the marriage is healthy. I'd seek some information and maybe counselling on how the two of you can get back on the same page. Great book is called "His Needs, Her Needs" and lays out 5 basic needs for every man and every woman in a marriage relationship and how when those needs aren't being met, there's unrest, frustration, etc.
And it talks about balancing those needs: He might not complain about the house being a wreck if he was having sex more often, but you might be interested in sex more often if he helped clean the house...
And you've got quite a full plate. If I was working full time again, I'd definitely hire a housekeeper and lawn service. That would be a nonissue. Of course a housekeeper won't come in and do your dishes every night, so you're doing a great thing with having the kids help out with daily chores too. Wonderful!
The "His Needs, Her Needs" book also recognizes that most relationships start to crumble a bit when kids come on the scene, and if both parties aren't careful, things really get out of hand and nobody is satisfied or happy. And the idea of "happy" brings me to another FANTASTIC book called Sacred Marriage. It's the only Chrsitian book on marriage that I've ever come across that "gets it." The author really hits home when he proposes that marriage isn't meant to make you happy, but to make you holy. Two fallen people living in a sinful world are basically destined for destruction (I know, sounds harsh...). You can do the normal thing and complain, get angry with each other, and grow further apart, or find ways to fall "toward" each other.
If you can, I'd see if he would be on board with establishing a regular date night (ours is monthly, but some folks do every other week or weekly -- I'd recommend starting with having one as frequently as you can). Once you've got some time together away from the chaos, hopefully walls will start coming down and y'all can come back together on things. Yes, the relationship and parenting gig is a team effort, but if the team never has a chance to huddle up, no one knows what the rest of the team is doing. It's that kind of lack of communication that makes people lose the game.