I saw how much trouble the green jellyfish gave you - they are completely immune to the regular thrown sword attack you were using.
You'll need a spell attack, which is activated by a right mouse click. (With controllers I think it is the right shoulder button but not 100% sure).

You are awesome sauce :) @worstcase11

By the way: Wind seeding works with the dust from the Mysterious Woman in Red as well, just hold down the 'E' key while you have it equipped.

And Matron Ye is standing on the small pier behind the inn after 9pm then you can trigger the quest of talking with her at night.