So exhausted, but don't wanna sleep!?

I get soo sleepy at night time, but never wanna sleep! I stay up anywhere from 12:30 to 4 and wake up every morning at 8:30. I have such a hard time getting out of bed in the am. I know I'm depriving myself of sleep; but if I get 8 or 9 hours of sleep, I'm so groggy throughout the day. If I get 4 hours of sleep, I function just fine. I've been diagnosed with ADHD, but not really sure if there is a coorelation between the two. I would just like confirmation that I'm not alone.