Toxic people have an interesting way of handling boundaries set on their abuse. They see our boundaries as nonsense and will accuse of us being unwell and bitter when we set them. These false accusations are based in the deflection of a truth about the person they are that they have no desire to face. The bitterness they speak of is simply their own bitterness directed out towards you. The typical response to the boundaries you set on them, is slander. These types of people hate being exposed, and will slash your character in all the ways and to all the people they think will hurt you most.
It’s a positive step in your healing when you can hold on to yourself and not react in the ways they predict. When you see that the only person reacting, and acting crazy is the toxic person, this is huge. Let them react. Let them rage. Let them play the victim. They are going to do this whether you like it or not. Disengage and ignore. The toxic people in your life cannot hurt you when you are comfortable in the truth that supports the boundaries you set. Too often we give these immature people far too much of our fear, anxiety, and power. Stand your solid ground and let them rage themselves out. The only person who looks bad when you do not react, is the person who should look bad. The toxic person.