i was on a sleeping pill (sonata) with clonazepam at the beginning of the semester and my psychiatrist told me that the combo could be contributing to my memory issues. i've stopped taking the sonata and use the clonazepam more sparingly and found that my memory has actually improved (i think).

i can also relate to being tired all the time. on the days i don't have classes, getting out of bed/actually thinking about doing something productive is a whole battle. sleeping feels so much better. i, despite my tiredness, am actually a morning person... i have the most energy when (well, if) i get out of bed and it exponentially decreases throughout the day until about 5/6 when i feel like i can't be out of bed any longer. my advice (or what has worked for me) would be to find the time in the day you have the most energy and try to stick your study sessions into there. it's not the perfect solution because i don't study/read as much as i'd like to... but at least it's getting done.

and also-- just staying motivated/setting goals is helpful, for me at least. if i know i want to get ace my classes and that x, y, and z have to get done i'll find a way to do it... even if, with my depression, it means doing the reading in bed as a pdf or via an e-reader. good luck! just know you're not alone in the constant exhaustion paired with the desire to study/do well in your classes