Help, I'm being evicted?

A few weeks ago my landlord started leaving notes on my door saying I had not pain my rent. My rent was paid up, and I had the reciepts to prove that. However, she continually called me, came to my work, and left notes on my door. I kept telling her I had the reciepts, but she said they meant nothing to her and she wanted "cash in hand" well 4 days ago I woke up to an eviction notice stuck to my door. It says that if I do not either: vacate within 7 days or pay 850 bucks, I will be taken to court. So, I called and spoke with the landlord, and she said "I could have sold the house 3 times by now and I want you out." Well, I am doing rent to own, and have only been in this house for 5 months. I think what is going on is that the landlord found somebody who would buy the house straight out rather than renting to own so now she wants me out. As I continued to speak with her the more angry she became and told me that now I had to be out in (((2 days!))) How is this legal? What I dont understand is if she wanted to sell it so fast, then why did she tell me she wanted to rent to own for 600 per month? Anyhow, what I am trying to figure out is if the eviction notice was something she had typed up on her computer, and was not notarized is it even an official eviction notice??? Also, now that I have moved out (within the 2 days as she demanded) am I still going to be responsible for this supposed 850 bucks? Or am I going to have to go to court and damage my clean record? Don't reciepts mean anything anymore?