PT needs sleep

Uni went back this week after our little break and it hit me like a tonne of bricks. I don't mean stress wise or mentally I mean physically. I was simply exhausted by the end of each day and the week left me pretty shattered. I am just hoping it was just 'getting back into the swing of things' rather than something that will become an issue. It left me so tired that I just haven't done any work outside of uni and I really need to get on top of it before I drown. I was even getting at least 8 hours sleep and having a nap on the train on the way home but it is not enough. Please please please tell me that this is not permanent.