Because my sleep gets disrupted by one thing or another and I have bad or just vaguely mentally draining dreams. I haven't looked forward to sleep in ages because I can't remember my last good one. I dread sleep now. I want sleep to be an escape from thinking or experiencing anything but REM sleep forces me to think and experience things via dreaming. 

The bad dreams often aren't even related to real life, just random mentally taxing situations. Like last night was me running away from an asteroid strike and not being able to find a single basement of shelter on the planet, which obviously isn't a literal real world problem I'm struggling with. But I woke up feeling so sick of shit cuz that was my umpteenth night of mental exhaustion and not getting any rest. I just feel so tired of it all that I'm crying inside, spiritually. I want to stop experiencing anything for a long time but it's literally biologically impossible. I cannot rest from existing and experiencing.