CrazyOX. Hello and welcome. I wish it were on a better note. But hello none the less.

Prescription mediation.
Because I am no doctor, I am only guessing. (You should bring this up to your doctor.)
I also take prescription medications. I wake up with a pit in my stomach often. Nothing as severe as what you have described.
I too have went a few days without medication. I have a zillion dreams. The medication severely hinders my dreaming. It sucks.
But due to the trauma that you have been through maybe you, being of the medication enabled you to have some dreams that you may not have had otherwise. Although you do not consciously remember them, you may have had them and therefore you still have the physical effects upon awakening.
When I say "them" I am guessing dreams that are very traumatic, nightmares.