Is It Normal to Fear That Your Reality is a Hallucination?

I have a really weird fear. Whenever I do anything, I'm always scared im not where I actually am. I think, "What if I had a huge accident or traumatic experience?" and "What if im actually in my school classroom or a hospital?" and I think im actually at home. Like I'm hallucinating where I am, and I'm actually in a class, and whenever I get up and do something, im not actually doing it, and I just look fucking crazy? or like if im singing one of my songs, im just mid class in song, but i dont know im in class. Am i really home right now? Am i acting a fool in public because I'm crazy? Is me having this fear making me more aware and its actually true im just "waking up" what happens when I come back to reailty and im in a class? Like is this at all a normal fear?