Trouble with in-laws staying at our house?

My in-laws live interstate. They chose to move away from our city as their two sons were not married and she wanted to be with her sisters. They visit twice a year and stay for weeks. Both my husband and his brother have small houses and although they think they are not getting in the way in my house there is stuff everywhere that I step over, the bathroom is dirty and I have to be polite and talk to them from morning till night. She washes up and tidies but it is just the general having guests in my face. It makes me not sleep and is very tiring. I am a person that likes my solitude and routine and for years have put up with having them stay, although each year I say less time that they can and it is now down to 3 nights only. I feel guilty and have told my husband that he must cater to them and if he wants to see them more to visit them at his brothers. This causes tension between us. I am dealing with an illness and I told my husband if he wants them to stay he had to do everything and I needed my space. They knew that I had the illness yet they still stayed and hung around putting pressure on me to organise things and go places as my husband didn't. They have left now, and I am drained and fighting with my husband. It is not fair. We did discuss that they stay in a hotel or move back to the city but they say they cannot afford it and only want to live in a house. Now they tell me they are going to give my husbands brother $40 per week so that my niece can go to preschool as his wife thinks that the fees are too expensive, but my brother in law spends all his money on top quality cameras and household goods which they know about as well. Why can't they save and spend the money on a hotel for a few weeks and then I can enjoy their visit more? I feel really trapped between my husband and his family and it is getting me down. My husband doesn't understand. Visiting them is a big trip and we run a home business and holidays are a rare thing. Help!