You just have to do the best you can with what you have. And log onto Flylady.com. She tells how to keep house in 15 minutes at a time, and also take time for yourself. Like the old saying is, "If Mamma ain't happy, ain't nobody happy". And if Mamma is totally exhausted, then she's going to be a nervous wreck in a short time.
My family does a lot of that having babies late..my Mom had her last baby 8 months before I had my first one. And one of my sisters went to her daughter's wedding still nursing her last one!! And my last baby is 17 years younger than my oldest!!