((((((((((Wendy))))))))))))
I am so sorry you are going through all of this.
Have you sat down with everyone and told them how upset the messy house makes you feel? Maybe a chart system would work with the kids.....write down on bristol board chores they are expected to do and use stickers, etc for marking them when they are done....if not, they lose something (tv, video game, etc) if it's not completed? I use that here and it seems to work with my boys. I am trying to think of other ideas and will try to brainstorm something.
Give Mark a kick in the pants for me and tell him to help you out and that I said so.

You are working long hours, raising a family and you need help. I wish there was something more I could do.
When I was reading your post, the one thing that popped in my mind the most is when is it your time hun? Do you have sometime each day that you can just focus on you? Put yourself on your list ok? You deserve it more than anyone I know.
Take care of yourself sweetie.
xoxo