Want to be a NORMAL sleeper

I am a 30 year old female who "requires" 10-12 hours of sleep minimum. It has been this way since I was a teenager. Last night when I got home I went to sleep at 1800 and only woke up when my husband came to bed at 2330 when I got up and got changed out of my clothes. I then got up at 0530, I hit my snooze button for 20 min. I had my morning cup of coffee to get me going, my Diet Mt. Dew to keep me going till I got home. I then had the rush of exhaustion that hits me everyday at about 1800. But I keep drinking my Dew and dealing with the yawns, 3-5 every min or so. I am normal weight and I am usually to tired to exercise at the end of the day and I can't get up on time no matter how much I try so getting up early is out of the question. I always have to use an alarm clock and I always set it early and always hit snooze because I can't get up. I have had a sleep study, which I was told came back normal, no sleep apnea. I have a normal thyroid and normal iron levels. I am at the end of my rope of always being tired. I want to know if there is another test I should have done, should I get a second opinion on my sleep study, what should I do. Thank you!!!