How Can A Bitter Person Overcome Bitterness?

I had a really tough childhood thanks to my mother.
I would just ignore it as a child, but I know I bottled up to many emotions, and now I am a hateful person who has people who wants to be friends but I dont want friends so I am very mean to them.
I dont like anyone or anything.
I was told 3 years ago that I was showing symptoms of a person who is becomming bitter, I ignored it but I wish I wouldnt have, now I am so bitter. I dont like anyone, I like to be alone all day long and I think everything is horrible, and I like to live in anger.
But I know this stress isnt good for me or my family.
So what do I do? I know I need to forgive but I “forgive” and when I see my mom again I get so bitter again.