Ha! I thought the same thing.
I'm glad you're getting things sorted out. It's not too late. I'm sure it won't be easy but it can be done. And as for claiming expenses for the children you currently have in care but have not yet provided reciepts for I would claim expenses and at the end of the year give them a reciept for everything paid that year. You don't have to provide reciepts on an ongoing basis, just once per year.