Similar to an existential crisis an existential loop is having a crisis on loop in which your brain finds fault in one existential theory leading you to another but the other proves the first one is not at fault leading you back to the second one which it'll state as fault, it's a dangerous Mind trap and falling for the loop will lead you to having depression, headaches, and even losing sleep. It's like having a song stuck in your head except this one prevents you from sleeping.
Perosn one: if God made earth than what made him?! And what made the thing that made him?!
Person two: dude you're in an existential loop.