Why do I sleep all the time?

Seriously. I sleep entirely too much.

I wake up at 2 pm ish, and end up taking a 5–6 hour “nap” later.
I’m exhausted all the time, and I don’t do anything to make me exhausted. All my body wants to do is sleep. All the time. I go to sleep, I wake up and I fall right back to sleep.
I stay awake at night, though. Midnight to about 6 am is when I’m most awake. But even if I do sleep through the night, I’ll still sleep all day.

Am I broken or something? Because this is really starting to bother me.
Anyone have any advice? I’m going incredibly insane.

I haven’t been able to work (or really do anything else) because of a chemical burn on my hand… I’m not being lazy on purpose.