Between a Rock and a Hard Place

I've never understood the phrase "between a rock and a hard place".

How hard is this hard place? Is it harder than the rock? Rocks are pretty hard, and it would be enough of a drag just to be stuck between two huge rocks.

But no. The hard place must be harder than the rock, or why mention it?

"Hey, I'd like to help you but I'm between a rock and and this huge diamond, which is much harder than the rock. Way bigger than the diamond I bought my wife, which is fake, by the way. That's why I'm calling it a hard place. Much harder compared to the rock. To be clear, I'm not stuck between two rocks, which are pretty hard, but between a rock and something much, much harder."

You never hear about how people extricate themselves from this difficult spot, which they are stuck in. I imagine some people have had to saw a limb off to get free. I think these "survivors" deserve a saying of their own.

"Hey, I'm not just going out on a limb for you, I've cut a limb off for you. You're welcome."