I didn't know there were states where landlords could prohibit subleasing entirely -- the fact that it's in a lease doesn't mean it's enforceable. You might want to do a search for organizations that provide information on landlord/tenant law; such organizations often provide information that might be helpful to tenants.
For what it's worth, the Florida landlord/tenant statute is
here. I'd probably read it and then decide what to do. It looks like under
this provision, you could be on the hook for all of the rent due for the remainder of your lease. Of course this is not legal advice, blah blah blah.