Don't worry folks. Its not as bad as you think.
I've had the same experience many times. The first time it scared the crap out of me. I didn't know what was going on and I thought I was blind and paralyzed. I fell asleep in a class in college and couldn't wake myself up. But I found that if I focus really hard on moving just one part of my body, then it breaks the paralysis.
Unfortunately, when I focused hard on moving my leg and managed to wake up in class, I accidentally kicked the desk in front of me and simultaneously flailed both my arms up in the air... Everyone looked at me, so I played it off as a yawn. lol
Ever since then, it happens to me occasionally at night, but I don't let it freak me out. In fact, its quite the opposite experience for me. I look forward to it and it excites me because I've been able to experiment and explore that mental state.
It is almost a sort of lucid dream/meditative experience. I find that as long as I stay calm, I can deeply access my imagination in a way that is not possible while fully awake. I can easily visualize mental images clearly and it gives me a heightened awareness of my body and every one of my senses. I can also effortlessly dismiss the paralysis and wake myself at any time.
However, I actively try to prolong the dream state when it happens to me, becuase no matter what I do, it never lasts for more than a few minutes.
So my advice for the next time it happens to you is don't panic, calm yourself down, and then explore your own awareness. If it does not appeal to you, then at most you'll probably wake up in a few minutes on your own. But even on the off chance that it lasts longer than that for you, just calmly focus on moving any one part of your body. When it moves, it will wake you up.
The mind is a mysterious place, so don't miss the opportunity to peel back your own consciousness and look deep into it.