Family issues

So for anyone who takes the time to read this,

I have a sister who is very ... mean.

Everything is an argument.

She lies about so much and she is extremely bossy.

The world revolves around her or so she thinks.

When I was pregnant with my son we argued so much and so often that I completely cut her off.

Once he was born me having to big of a heart give her another chance.

He’s 10 months old now and she’s back to her old ways.

I am trying to conceive and got my first positive test today.. and I’m so worried to even tell anyone because I don’t want her trying to take over my life again.

My first pregnancy was so stressful because of her and I don’t want that again.

If I cut her off I lose a couple other people too because they’re always on her side but at this point.. ugh I just don’t know what I should do...

Any advice?