Waking up feeling sick, what's my problem?

naturalistic this is called the fight flight response. This is wear when you get nervous or scared their is a release of adrenaline and in your case blood rushes away (butterfly's) from the stomach and other internal organs to fuel the muscles. This is an over reaction but its how the body prepares for events that are scary or nervracking. In your case this rush of blood away from the organs makes you feel queezey.