to be sleepy all the time?

So today I had to go get patient info at the hospital for clinicals tomorrow.  I got up this morning, studied a little, took a shower then decided to lay down because I just could not keep my eyes open.  Much to my surprise it was time to get ready so I did.  Got done with my research and went to get the kids.  Here I am ready to get started on my homework and my eyes are heavy again....Is it possible to get TOO much sleep?  I don't feel I have, because I don't get that much.  It just seems no matter how much or how little I sleep, I am always sleepy. Is that normal?