Hi - This is a bit late in replying you, so my guess is you have already figured out the answer.
However, if not, and just to answer the question posted - yes, y ou should be able to change your mind and not sell or not rent-to-own anymore. An agent can't force you to sell a house unless you have already signed a contract with a buyer (whether a regular sale or rent to own), then you will have to cancel that contract and possibly compensate the buyers and/or your agent (since he/she found an acceptable buyer for you).
Another thing to be careful about is to read the listing agreement you signed with your agent to see if you are obligate to pay him/her any fee/expenses they may have incurred, etc.
Reading and understanding the contracts you are going to sign (before listing) and/or already signed is vital in doing business.
Hope this helps. Please do not hesitate to call/text or email me wiith any questions