where do i go :(

i beat grandmother silk and got what assume to be the default ending. the only loose thread i had after that was the mist which i couldnt figure out how to get through. eventually a just googled it, beat phantom, and now im just absolutely lost.

theres only 2 things left that i can think of. in the far fields right of pilgrims rest theres a door with some beast behind it i cant get through, and in the coral tower i used the conchcutter in the room with all the soldiers which made a noise and saved the game but didnt do anything else.

with NO/MINIMAL SPOILERS can someone guide me to the direction i need to go next?

https://preview.redd.it/64krvh0vt7tf1.png?width=1491&format=png&auto=webp&s=5424508594ef2fb5a19308418ddf2941da015a04