What you need is some structure, routines, and discipline for everyone in the house, including yourself(this is said as politely as possible, and with a sympathetic smile).
We had/have the same problems here at my house, both before when I was a sahm, after I went to work 40+ hrs. a week, and still have it now that I haven't been working going on a month. I just need to get back in the game and get the control back.
Several months before I started working, I had become fed up. I was basically a single mom raising 3 kids while my husband worked out of state for 9 mos., and my kids were the next thing to lazy. At my wits' and rope's end, I found Fly Lady again http://www.flylady.net/ . My family thought I was stupid, and once they chucked the idea out the window, and I realized they wouldn't take it seriously, I finally just implemented the "program" in ways they wouldn't recognize as Fly Lady. FINALLY, I had some structure going on, some routines, and things were going better....then, I got a job lol. You can be a Fly Baby working mom also, but I didn't have the time, energy, or self-discpline to figure out how to make it work being a working mom, so, my house went to heck in a hand basket, and is still there. Good thing it's time for Spring cleaning(groan, gasp)!
Anyhoo, my point is #1 let go of the perfectionist mentality, that "perfect" idea you have for yourself and everyone else. Just try and take one day at a time, maybe take some time and write down some goals, both long-term, and ESP short-term. Sit down with your husband and explain to him you don't need him to do everything, but both of you figure out what he can take care of and what you can take care of, and both of you assign yourselves these tasks. Try and calmly and non confrontationally emphasize to him that to be a better wife and mom, you need some help so you're not so overwhelmed. Suggest to him that once everything is on track and less chaotic, then you two can plan a nice little weekend getaway somewhere, just the two of you--work that in to your goal planning somewhere. The 11 and 7(8) yr. olds can definately take care of their own rooms and puttting away their own clothes, and getting their things together for the next day the night before. They can also help load and unload the dishwasher, take out garbage, fetch lods of clothes, do minor household cleaning tasks, the 11 yr. old can help the 2 yr. old with baths and with pets, etc. You can make it a game, contest, job from which they get paid, whatever, just enlist their help.
You just need to "mom up" :o) and make sure that they understand that to have rewards, they need to help out. Make sure that they understand that they live there too, and help to make messes, they can help clean them.
AND, if your husband can't be brought on board, then maybe you can suggest counseling from the clergy rather than by a therapist/medical professional. I think that if he loves you, you both will be able to work something out.
And if you need someone to talk to who understands where you are because I've been there too, then feel free to message me. Maybe privately I can help you come up with some solutions. I still implemented some of Fly Lady's suggestions even as my house tumbled into the abyss(I always knew where I needed to be and when because of the calendar idea lol) and will go back to implementing the rest once Spring cleaning is done.
My future home based business will be about helping people just like you get some control of their lives and be way less stressed. I'd be glad to try and help(I'm not in business yet, so no charge, really!), just to help you get some measure of calm back into your life.
Take care, and best of luck,
K. W.