You should consult with an attorney that practices in real estate in your area. Typically, an agreement for deed, which it sounds like you have, must go through the same foreclosure process that a mortgage does in order to get the property back.
Every situation is different and no one should rely solely on information received from the internet. If you have any questions about your legal rights, you should consult with an attorney that practices in that area of law. Nothing in this message should be construed as creating any type of attorney-client relationship.