Advice for better sleep

I wouldn't worry about 9 hours being too much sleep, some people need more sleep than others so the average sleep needed may not be the healthiest amount for you. In terms of sleep quality, eating foods high in zinc and magnesium can increase the quality of sleep by lengthening the REM (dreaming) part of sleep. REM is the sleep phase where most of your memory and learning is processed so it is very important.