Can anxiety and tension cause a hungover feeling in the morning? i've had sleep studies - not apnea.

Maybe: If you don't sleep well related to your anxiety/tension, then you could wake feeling unrefreshed inthe morning. I would also consider other things besides apnea though, for ex are you taking meds? Supplements? Drink alcohol? All of these have the potential to interfere with sleep. Your doctor can review these things with you. Good luck!

Poor quality sleep: The symptoms that you are having are referred to as sleep drunkenness. Anything that can cause fragmented, poor quality sleep can cause this. The most common causes not related to drugs or medications are depression and idiopathic hypersonia with long sleep time. It can certainly also be seen in narcolepsy and circadian rhythm sleep disorders, and the interplay between anxiety and these conditions is considerable. Please discuss this with your treating physician and if necessary return to sleep disorder specialist.