Still Tired After 12 hrs.of sleep?

I been sleeping a good 8-12 hours a night and I still wake up groggy and have brain fog throughout the day and I also been getting short of breath and fast heartbeat for no reason.I also get tension headaches and just feel like crap.I am only 22 and dont drink or smoke and dont do drugs at all!! I am not depressed but all of this is making me stressed and is depressing because I cant live a normal life.I been tot he er and doctors and had a million test and I have high cholesterol tyiglycerides and high bp on occasions so I take a beta blocker which dont work any more.What could it be??