clutch issue

I just bought my rx8 a few weeks ago its an 04 6 speed and I was driving on the interstate and all the sudden I couldn't accelerate and the clutch dropped to the floor. The engine would rev and sounded fine so I pulled over to check it, engine was fine so I figured it was the clutch. It would start in first with the clutch pressed, at this point it had come back up but had very little resistance. After I released the clutch while in first gear it never stalled as well as allowing me to switch into any gear without pressing the clutch. While in gear the rpms would fluctuate between 1000-1500 and would idle fine in neutral. Any ideas? Is it possible it is just the slave cylinder and I won't have to replace the clutch?