Living alone now for 2 years and sometimes i get paranoid.

Maybe this post will sound very immature, but i don't deal with much problems living alone. Actually everything is perfect, as i suggest for most of the people here. But once i got from the cinema home (we were watching a horror movie), i couldn't fall asleep and got really paranoid about someone being in the flat with me, didn't sleep the whole night. Afterall after this happened i was exhausted the other night and forgot it all including the movie that made me paranoid 😂. But after this even time to time i get paranoid and can't fall asleep. At least twice a month, i haven't faced problems like these in my life. Am i the only one that has that kind of problems while living alone? How do you deal with it, because it messes up my sleep and it impacts my work and general life after those episodes.