85 300ZX Non-Turbo - Transmission / Clutch Problem? :(

Hi Everyone,

Thanks in advance for reading my post...

I have an '85 300ZX non-turbo, manual transmission. It has (gulp)
192,000 miles.

I rarely drive it, but when I took it out today, here's what
happened:

1. Started up fine, able to put the shifter into any gear with no
problem.
2. Began driving in 1st gear, no problem.
3. When I pushed in the clutch for the first time, I heard a
"whirring" noise and maybe a "clunk". I stopped the car and left the
motor running. I could not even move the shifter in to any forward
gear. I was able (with some horrible grinding noise) to get it into
reverse and then before moving anywhere I could get it into 1st. I
limped home in first, but I didn't dare to push in the clutch since I
knew that I wouldn't be able to get it into gear again if I did. It
was making a strange noise (whirring?).

I did check the clutch master and it does have plenty of fluid.

Any ideas? Maybe clutch release bearing? This car is obviously
ancient, so anything's possible.

Thanks again,
Bill