Do they have the right to sue me?

I live in Florida. My dog has cancer and her bills are enormous... and I got behind on my rent. I received a 3-Day Notice to Vacate (stating to pay or leave), and I chose to vacate the premises and moved in with a friend so I could better manage my finances. Yesterday I received a summons & complaint for owed rent & fees. Also, the amounts listed in the complaint are incorrect. Do I have a chance at fighting this?