Fed up of my boyfriends family

Basically me and my boyfriends brothers girlfriend were friends well that’s what I thought.

But now she’s constantly slagging me off to my boyfriends mum making up lies , telling her information that I’d want to tell her myself. Saying this and saying that.

She is also slagging me off and making lies to one of my old friends they all live close together and every single day I find out new things like she said this. She said that.

Even telling me that my boyfriends family hate my guts.

His mum sits there and slags me off aswell. What should I do. So fed up of this. I’m pregnant and I want them part of the babies life but they make me so uncomfortable

Tomorrow they are having a Christmas party and I’m not invited. They are going abroad and deliberately booked it on my birthday and didn’t even invite me.