I am always exhausted even with good sleep what could be the reason? i also have horrible memory and i don't know why. help please!?

Many possible causes: There are many possible reasons for these symptoms including sleep apnea, anxiety, depression, caffeine intake, poor sleep habits, stress, etc. Please see your primary care physician.

Fatigue: Numerous reasons for exhaustion & memory problems, from physiological such as infections, to psychological such as depression, to immune system compromise, to deficiencies such as minerals/vitamins. Recommend thorough workup by your primary care doc. To explore possible causes. Good luck.

OSA?: Both excessive daytime sleepiness and memory problems are associated with obstructive sleep apnea. Many people assume that just because they are in bed for more than 8 hours a night they are getting good sleep. There is only one way to know for sure. That is to go to a sleep physician and is necessary have a sleep study done.