I'd say from your description of the episode and how you reacted afterwards, you've more likely to have experienced 'sleep paralysis' than a type of seizure...
Sleep paralysis is the temporary inability to move or speak, they can include hallucinations that are visual, auditory, physical sensations etc and they typically happen when you're waking up or falling asleep, they actually only last a few seconds or minutes but can be very frightening and feel a lot longer than that.
Sleep paralysis affects people of all ages though most common in teenagers and young adults, but they say it's not uncommon to experience sleep paralysis at least once or twice in your life time. They're not harmful or generally a sign of something serious, they are usually to do with sleeping habits or poor sleep quality eg not getting enough sleep, irregular sleep patterns etc
It is unlikely to reoccur but IF they keep happening you should consider bringing it to the attention of your family GP.
Hope it helps......JJ