You can not ask an attorney for advice about a written document you signed without showing it to the attorney. I do not expect you to get any advice about this contract otherwise,.
You also do not specify what the landlord is suing for? just for damages? for eviction, for rent?
Assuming the landlord is suing for damages for your refusal to buy the property, then you must continue to pay the rental if you want to live there. If you do not pay the rent, the landlord can separately file suit for eviction.
This is general information and not a binding opinion since we have not seen your contract or the swuit.
This comment does not create an attorney-client relationship. The law and its application by the courts is constantly evolving and changing. This discussion is not to be taken as a definitive guide, and should not be relied upon to determine all fact situations. Each set of facts must be examined separately with the current case and statutory law analyzed and applied accordingly.