- First, see if you can find other employees in the same situation. Being a group helped us. - Document everything. Commit on git first thing in the morning, and before leaving. Write down every conversation you had right after you had them—we tend to forget very quickly. Dump your calendar and emails regularly. You can find scripts to dump Slack too. If your boss has written anything abusive them, it is also a good idea to take screenshots. - I guess moving is not an option for your family? Otherwise start looking in other markets. - Freelancing is a good option otherwise. I know it sucks to do this on top of your job, but you only to save enough to get yourself out of this.
Once you’re out, and only when you’re out, find a good lawyer. Do not hesitate to sue. It’s not greed, it’s reparation for the abuse. You deserve it.
Good luck to you.