Ahh, I want to help but I don't know what to work with. This is the kind of thing that would be really easy to help you wish if you had some video footage of you playing.
The Hag: are you talking about the fight before she retreats underground or in the room at the bottom with the cage? In my playthrough that bottom room she was bugged so I can't really comment on that.
The Phase Spider Queen: (I think that is what you were referring to) - Yeah this is a tough fight. Using a poison resistance potion on every member before the fight (they last until long rest) will help a TON. I only used one but that would be my first advice. Next would be to make sure you use some AoE (burning hands, bombs, other throwables) to hit all the baby spiders at once. I took out the regular spiders first, then focused on the queen when I wasn't surrounded by the babies.
