Natalie, It is amazing to me how clueless some people are. I am really glad you spoke up! I don't have many friends who have had surgery and those that have had outpatient procedures with quick recoveries. Joint replacement is not that! It is a very long recovery, and you are still early in the recovery process.
Is there an older teenager, a college student, a mother with kids in school, or a retired woman you could hire to help out for a little while? A lot of the mothers I know would love to work a few hours a week around the kids' schedule, but it's almost impossible to find that sort of thing. If that would be too expensive, maybe you could work out some kind of barter arrangement. You could fulfill your part of the barter after you've recovered.
I hate that friends or others you and your family know haven't stepped up to help. Another possibility -- I don't know how it is in the UK, but here high school students, scouts, and teenagers in church groups have to perform a certain number of volunteer hours. If you could get the word out, maybe you could get some help this way. I sure wish I lived close to you and could do something myself!