Everynight i fall asleep with the tv on and wake up with it off with no memory of turning it off. is this common? or should i worry about memory loss?

Worry is useless: If anything you might want to address w/ concern it could be your life style. That is not a good habit to get into for healthy sleep hygiene. And, if you do suffer STDs your life style choices thee may need attention too. Use protection when you have sex. ALWAYS. You don't mention if you are likely to have had alcohol or other drugs before falling asleep - but that's more likely than memory loss