I feel for you, I lived with several mothers of my partners'.
It's rude and toxic behavior you describe. You should not tolerate this, people only get worse when they are unpunished, and foremost your partner should take care of two people whom he loves (like I'm responsible for my parents saying bad things about my partner and I will never allow them to be rude with him). You can't deal with this without him and he seems... not looking at your problems. For me, it would be a bad signal.
You should speak with your partner. He should be on your side. No way you can't talk to him if you are really together.
And find some other place to live or go to your parents.