Sleeping paralysis and muscle jerking. Seems contradictory. How does that work?

Normal sleep. Sudden jerks in sleep are normal parts of sleep related arousals. The sensation of awakening with being unable to move is called sleep paralysis, and is also not dangerous. These can be signs of rare disorders like narcolepsy, but much more often are due to sleep deprivation. Try for 6 to 8 hours of sleep nightly.