Ugh, that is so frustrating. I'm impressed you found the time and energy to write in grad school--that's the struggle I'm having now!

I know my writer's block is worst when I'm not really inspired by anything. This may be because real life events are just taking up too much of my attention, or because I've gotten into a rut. Maybe try doing something outside the norm, like watching a movie or reading a book that's not your usual genres, or trying a new activity? That's helped me in the past.

I hope it clears up for you soon!