I’ve had lifelong intermittent sleep paralysis and it’s one of the worst feelings. Happened to me yesterday during a nap actually! I went to get up, and only my right foot moved an inch (or so it felt). I had to count to 3 and muster all of my strength to try to move again, and it didn’t work until the 4th time, when my body finally giggled a little.. enough to wake up the rest of it and free me once and for all.