I'm sorry you're going through this.

One thing that is often overlooked is that if you stand up to a bully, they'll treat you better in the future. My stepfather loved to ridicule everyone so I grew up cowering to him. Finally the time came when he was being snarky about something so I challenged him on it. It was amazing how much better he treated me after that. Same with the president of our HOA. After he found out he couldn't bully me, he doesn't.