mortgage debt

I have a property in the state of Florida. The loan is an interest only loan - which has become too expensive to afford. A real estate agent recently told me that the most she could get for the property was $115,000.00 - however, the mortgage is for $240,000 - which is a loss of $125,000! I could afford the $115,000 - but I cannot afford the $240,000 mortgage, which has been increasing every time because of the interest. My question is this - is there any way that I can request the bank or any mortgage company to lower the mortgage to the $115,000 that the property is now worth. If not, then what can I do - since the increasing payments are too expensive to afford anymore?