Then I somehow end up in a secret room and then teleport to the underdark, where I get owned by some large chicken creatures, I kind a understand that this is not for my level, but since its a completely different dungeon, why should it even be under hag's house? Didnt understand the logic here, reloaded and just went deeper to the hags house.
What? Do you mean this place?
Yep, this one, didn't have a slightest clue why did I appear there and how that's connected to the hag. Seemed like totally separate and new place that should be part of some other quest.