My mother has been an abusive narcissist for as long as I can remember. Without turning this post into my backstory, I no longer have any sense of self worth, cling to others for validation, and am struggling with ptsd and a disordered personality as a result of the dysfunction of my household.

Now I have a partner. He's extremely sweet and caring, and he has a very close positive relationship with his family. I'm trying to get to know them, but I find myself being instinctually hostile around them, his mother especially. I'm always expecting an ulterior motive, and I'm always expecting her to take him from me like my mother took pretty much everything I had. It's led to my partner being a bit insulted that I assume these things out of her, which I don't blame him for, but I don't even know how to help it. Is that normal? What should I do?