You have to proceed carrefully, collecting blood vials and going back to the hunter's dream to use your blood echoes (level up with the doll). The doll will be active when you have at least 1 insight point. You can earn one by consuming "knowledge" things (don't remember the name in english, it's a skull).
To avoid redoing the same area again and again, you can open shortcuts. Try another way, near the crows, behind wooden boxes, there's a hidden passage.







