hey! no worries!
u r not meant to be there yet. When u r going up to lovis tower, there is a way down on the stairs/ladders that is kinda hard to spot. I made the same mistake. When u climb up ladders, then u see the path curving up to the chamber with skeleton, that is where it is hard to see but there is also a way down, where is another chamber and lovis. He will have what u need to get into the top chamber. lol no spoilers.
All the best.
push the four buttons and the door will open again. Beware; one of the buttons is in the burning room.