That was sleep paralyses, yes.

I once had one, where I dreamed three times in a row, that I overcame the sleep paralyzes and could sit up in my bed, only to wake up again in sleep paralyzes every time.

And another one similar to your experience, where I saw my screen with my mind imagining a video playing there.

The really scary ones are those, where you see dream creatures in reality though. Never had that fortunately.