Can I sue my landlord for a false negative reference?

My two year lease is up at the end of this month. It is a fixed term lease in Missouri. Missouri statute states that no notice is required of the tenant or landlord for a fixed term lease. The law also states that if a tenant does occupy the property after the lease expiration date, the landlord may charge double the rent for those months. We found a new home for our family, and everything was going well until the property manager of the new rental called my current landlord to inquire about my tenancy. I have paid rent on time every month and have maintained the property, The landlord advised the new property manager that she required 30 days notice and that I had not provided that. The property manager told me this. The landlord also called and told me this. She told me she would not give back her security deposit. I told her I would cancel the professional cleaning and professional carpet cleaning if she tried to withhold my deposit. She then called the property manager and told him that I made threats against the property. The property manager declined our rental and advised that the negative reference by the landlord was the primary reason. We do not have a backup property. We will probably NEVER find the deal we got again. This landlord caused significant damage to my family and has sabotaged our oportunity. I had taken time off of work to move, and I start a new position in my company on 6/1 and will be unable to take time off again for at least 3 months. I have written and tried to reason with the landlord, but she is betting that I will not take action. What recourse do I have? Please help!