I usually don't take naps, but within the last few weeks I have been taking naps almost everyday for about two hours on average. Every time I wake up, I feel sick. I'll feel everything from nausea to headaches to exhaustion.
Try Googling hypothyroidism as well. Your symptoms sound similar to that. Then arm yourself with a list of symptoms and get to the doctor, preferably an internist or a naturopathic doctor who deals with thyroid problems.
Have you been waking in the morning feeling just as tired as when you went to sleep? Do you have a headache in the morning when you get up. What has happened recently that has caused a nap habit? Google sleep apnea to see if you have any of the symptoms. Do you have a sleep partner that has told you that you stop breathing while you're sleeping or that you snore? If youm suspect that you have sleep apnea get to your doctor for a sleep study referral A.S.A.P.! Other than that are you overheated while you're napping or near something you are allergic too? Good luck & feel better