Concentration problems!!

I really don't know what is going on but I CANNOT concentrate on anything today.... ugh... I have a exam tomorrow and really need to study but I keep finding thing far more interesting to do (reading all the topics on glow for instance) and my head is so full with thoughts, I can't stop thinking them. grrrrrrrrr...... I really need to study or else I have no shot at passing this exam and I don't want to do it again. It's too expensive to do for a second time 😫 anyone tips?