Dreadful feeling

Do you ever get a feeling that something huge is about to happen?  Something life changing?  And with the feeling all you feel is dark and dreadful?
I had this feeling last night.  I wasn't feeling very good yesterday, having an off day, and last night when I went to bed I just got hit with something.  A horrible feeling, that I couldn't shake.  Something felt very off.  The thing that kept popping into my mind was it had something to do with me.  So, I then I started going through everything that could be wrong with me.  Maybe I have skin cancer, or maybe I have a tumor, or maybe ovarian cancer, or maybe ............ These thoughts just kept going through my mind.  Needless to say, I didn't sleep last night.  And I am really hoping that this was something just in my mind. 
Thanks for letting me get that off my chest.  It helps to write about these things.