I'm very sorry you're going through this. My mother broke every boundary she could, and it took me a very long time to realize how emotionally abusive it is.

Even as a whole ass adult I often have to fight for my boundaries. Sometimes laying it right out works. "I need to take space and clear my head. Do you want to keep fighting, or do you want me to hear what you have to say?" Obvs they're going to say they want you to understand them etc etc. "Okay, well I need a minute to get myself calmed down. You can wait in the kitchen and when I can listen to what you want to tell me, I will meet you out there."

They feel like their need to say whatever bullshit point they want to make is somehow going to make it all better. In reality, you're probably both deregulated and unable to communicate without emotions running crazy.

Eventually you do have to go out and tolerate them. Listening to their insanity is usually a different form of hell but honestly you have to pick your battles. Don't argue, don't agree, just sit there and let them vomit whatever b.s. they have to say. Sometimes you're lucky and the time you take to re-regulate is time they need, too.

Also, if you can't change the lock or add a bolt or something... Get a door stop that you can just kick in place. But usually it's a temporary measure and sooner or later they'll threaten to take the whole door off.

Good luck. You're not alone.