Howabout you get someone in to do a complete house clean to start off with (you may need to contact an agency for this- ask for local recommendations) then get someone to come in for 2 hours once a week to start off with and see how it goes?
You might well find that once a week is not enough as you are struggling to do it for yourself so wouldn't be a bad idea to have someone in for 2 hours twice a week if you can afford to - or at least close off the rooms that you don't need to use once they have been cleaned the first time, even to the point of using dust sheets!
You have received a windfall ...
