Okay I figured it out myself.
For anyone who gets stuck in that loop... To get to the exit, you need to use the mirror to the "entrance hall" and then continue south. The reason I got stuck is because the camera automatically zooms out when you're walking down and the path is hidden by Lava.
To compound the confusion, there is a chest down there making it seem like a dead end only for the chest. But in reality there is a tiny strip of walkway you need to click on. This leads to another mirror and the exit.
God I spent a solid hour+ on this part. I'm so salty now.
