Apparently you need to spend some energy to fall asleep. So if you don’t have even the minimal energy required to fall asleep, you can’t do what you dearly need to energize yourself.
I have a similar problem these days: I can’t read. Reading helps me face my loneliness and ultimately relieve it a bit. But to read, I have to shun all interaction and immerse myself in a world where others can’t reach; I have to step over that initial threshold of loneliness to make myself feel less lonely. And it seems like I can’t take even that much of loneliness.
Expectations can hurt. I subconsciously expected and consciously hoped to relieve my loneliness a bit. But there were only expectations and no realization. A wound was opened but left unclosed. And boy, it hurt a lot.