Help, my clutch has fallen... blah, blah

Alright, about 3-4 days ago, I noticed that while driving the clutch has lost some of it's "spring". over the last 2 days, the clutch doesn't seem to always spring back up. this happens without any other noises at all. when it happened today, I was able to drive home by shifting quickly and when it wanted to fall back down, I could bring it back up with my foot under the pedal. Once it even fell all the way to the floor and I had to sop at a light and pull it back up with my hand. I replaced the clutch master cylinder about 15,000 miles ago or so due to the same problem. Is it possible for this to happen again so soon?

 

Having a similar issue only I haven't replaced it prior. I've done the slave cylinder which did not seem to fix the problem.

What ended up being the problem?