Can anyone tell me what the heck this is?

I received this email today, it went into my spam folder but I noticed that it was sent from myself which was really weird? When I click on the sender details it literally says my email address and it was sent from myself, to myself. I don't even understand how that works... But the context of the email is rather worrying and very jarring to read. It obviously looks like it's just someone trying to use a scare tactic. But just wanted to make sure if this is a well known scam or something? Because I have never gotten an email like this one before. Thanks.

I received this email today, it went into my spam folder but I noticed that it was sent from myself which was really weird? When I click on the sender details it literally says my email address and it was sent from myself, to myself. I don't even understand how that works... But the context of the email is rather worrying and very jarring to read. It obviously looks like it's just someone trying to use a scare tactic. But just wanted to make sure if this is a well known scam or something? Because I have never gotten an email like this one before. Thanks.