Exhaustion

I am exhausted. I have had some trouble sleeping over the past few days and I can't figure out why. A myriad of wonderings has passed through my mind, several times. Is it because of the creepy presence that's felt in my room from time to time? Is it because my room isn't dark enough? Is it because of the fact that I am now 3 hours ahead of the time I'm used to going to bed? Is it because my mind is always working, in 2 languages? Is it because I am always in "alert mode" here in Brasil, waiting for the proverbial ax to fall? Is it because I am anxious about getting to sleep?
I have no idea. And it sucks.