It's not and it doesn't, mental stability is relative from one person to the other, your issue is and should be treated just as seriously as anyone else's.
With that out of the way, are you dreaming at all beforehand? Specifically, anything related to loss of control, or deep anxiety, or do you have something major going on in your life? You don't have to answer here, but those types of things can be enough to cause something like this, I think.
Not currently going through it, but I remember going through something similar during high-school. We got a new Chemistry teacher who really didn't like my "love the concepts, hate the math" approach and made it clear that she was out to "fix" that (ideally, by holding me back a year). I remember waking up every single day with a brief (2-3 seconds, with the rest being the trail-off) shock of sheer terror and anxiety. I didn't need to dream about it, I didn't need to have Chem classes that day, even happened during the weekend. And I remember it stopping at around the time when I gave up trying to understand what I was studying and accepted my fate.
This is why I asked, maybe you have something similar in your life, some sort of overarching worry. And it's not even necessary to be consciously aware of it, your subconscious has it all covered.