Also, you don’t ALL need to be home with your MIL all the time.
For instance, you could go grocery shopping or run errands by yourself (MIL stays with kids) or MIL could go do grocery shopping by herself. (And zip your lips when she brings home “the wrong” stuff.) Or when your husband is home, you can go for a nice walk, do a little yard work, or go to the gym–whatever would be a good excuse for alone time in your particular situation. Naps are nice–if feasible. I also recommend an early bedtime. Once you put the kids to bed and get house stuff done for the night and everything ready for the next morning, there’s no need for you to stay up late entertaining–you can tell everybody goodnight and disappear. There’s no need to go straight to sleep, either.
My current preferred formula for hosting family is 1) planned morning fun 2) lunch together 3) afternoon off 4) dinner together. That’s plenty of togetherness. Also, the grandparents in our family have been staying at hotels for a while (but that does keep visits pretty short).
I’ve known my in-laws for 18 years and I made so many mistakes it’s not even funny. (And so did they, of course.) But you can do better. You’re making a lot of rookie mistakes. Basically, when somebody dangles a shiny object in front of you, you don’t need to bite. Also, remember this is not the Best Daughter-in-Law in the World pageant. You aren’t that important. Your MIL is there primarily to see your husband and any kids you have. Also, bear in mind that she may want to spend some time with just your husband, so try to set up an opportunity for them to do something together.
Good luck!