I don't have a backstory or lore, I have mental health issues and sleep debt.

Sounds like a LN Sorcerer to me.

I submitted a FOIA request for my character's backstory in a campaign only to find out that the wizards had redacted the incidents I wanted to know about.

Or, an unwitting warlock who thinks he is one.

When your DM wants you to "expound on your PC's backstory a little"... Be afraid. It's not unlike pleading your case to the arresting officer, much of the time.

Sleep debt is just day-off credit.

I used to always take amnesia as a character flaw in World of Darkness games.

There is that potential, depending on your build. Makes me wanna DM again. An all warlock party where nobody knows that anyone else is a warlock would be the silliest sort of fun

Better still: all the players think they've made bard PCs. 🤌