If you will be OK. finically then I would say let them go. Especially, if their behaviour is stressing you and your child. It is already effecting you and in no time you won't like having a day home in your house and this will affect your business and finances as you might want to close down cause you worn yourself. It's really not worth the stress so let them go. Meanwhile, keep looking to fill your spots which I'm sure you will do that regardless of me saying good luck.