Better sleep or energy drinks?!

Hi, I have a problem...I always am very sleepy when I'm doing anything school related! Unless something interests me or is very fun, I cannot focus on it and will fall asleep. This happens in most of my classes and when I attempt to do homework. I get around 7-8 hours of sleep a night and eat very healthily, so I cannot see what the problem is! My only theory is that I'm a very light sleeper (I'm in a college dorm and have to sleep with ear plugs or else my suitemates will wake me up, I don't even have roommate)- so the sleep I get is usually very scattered. Also if I let myself sleep in for as long as I want to make up for it I will still be very groggy through out the day.

The only solution I've found so far was today. After getting 8 hours of sleep and a good breakfast, I fell asleep in my 8am class, chemistry. I had calculus in 15 minutes and refused to fall asleep in that class too, so I went to the vending machine and bought an "Amp" energy drink. I've never had an energy drink before but I finished it before/during class...and I've never been so focused in my life! I not only took great notes and took everything in, but I decided to go to the library and literally read/caught up with classwork for five hours straight (normally I'd go to the library, start nodding off after 40 minutes and then have to do something like go to the gym to wake me up). This worked really well but I know that energy drinks are supposed to be unhealthy for you. Is there any healthy alternative that's effective as Amp (maybe five hour energy?) I've tried caffeinated products...they work decently well but usually only make me feel awake, not focused, and wear off after a little while. Thanks so much!