Ask a landlord-tenant lawyer and get answers ASAP
I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear that this happened.
You're only liable for the rent up until the landlord stopped seeking a new tenant. If he's decided to sell the property instead of renting it out, then that cuts off your liability under the lease. He does have an obligation to mitigate his damages. It IS legal for him to sell the house, but he can't keep charging you rent while he lets the place sit empty.