Need guidance!!!

My roommate moved out most of his belongings and currently stays somewhere else. However he is still on the current lease with me. He is forcing me to pay the entire rent by myself because I refuse to destroy my good credit. He refuses to sign the lease agreement until he has the deposit. I can get someone to replace him and pay the deposit easily because the area is nice and the room is nice. I do not trust him to take the money and just run with it and still not sign the agreement.

What can I do in this situation? Some people said I can sue him for not paying or what not but I really don’t know what I can do. BTW the state is Florida