Don't quit. Take a vacation with girlfriends,

leave the kids to your hu*****and for a week or two. You will get some rest; and your hu*****and will learn how difficult it is to take care of kids. (Before leave for vacation, prepare some food for them and tell your hu*****and it is OK to get take-out every day.)

I have a girlfriend had the similar situation. (She took too much responsibilities.) At the end, when they learned that divorce was extremely bad for kids, they dropped the idea. 5 years later, they are quite happy together.