This is a good sign. It may be a case of whittling it down until it gives up. You could be closer than you think. I’ve had parasites that took months to remove, and each attack pushed it a bit further away. So I would keep going with this.
Be aware that it may try to hide to avoid being banished, it’s annoying but just keep going
Death isn’t a real thing, but you can make it so he might as well be dead as far as you’re concerned.
Visualise it in front f you and attack it with any weapon you like.
I like to burn them with fire, I talked about it here.