I know what you are going through. I have severe depression along with anxiety and when everything was real bad with me I would wake up in the middle of the night and not able to fall back asleep along with a nervous stomach and feeling sick. Things have gotten better though, but I still have anxious thoughts that still bother me. So I believe that you may be having some sort of anxiety, but I am not a doctor so if you haven't already I'd go and see one to see what they say.
