your clutch is wearing out to its last point, when it does replace the friction plate and pressure plate, remember to use antisieze on the splines on which the clutch plate is mounted to otherwise it may chatter on release.
You can try replacing the clutch fluid, its a simple system with a very short path. However I have seen a problem like yours in which the soft rubber pipe to the clutch has corroded internally causing a hard to press clutch.