I just cant say GO GET HELP
You cannot help her. And the great thing is, it is *not* your job to help her.
She is your mum ! Which means she's an adult. If she has unadapted ways to deal with the world, this is in no way your fault. NN is right when she says the only thing you can do is learning strategies and communication techniques to interact with her.
NN also mentioned boundaries. Boundaries are very important for everyone, but more so for people who were raised by a BPD parent. We were groomed to think that we cannot have boundaries. Becoming an adult ourselves, we need to teach ourselves that we can and should have them.
Boundaries are personal. Your boundaries are not my boundaries. It's like with colors : some people like green, some people prefer red.
A healthy boundary in any case can be that we don't want to be yelled at. Or that we don't want to be insulted.
With BPD it is very important we stick to our boundaries. If we don't, we show them that we are not really serious about them, and the behavior we draw a boundary for, will get worse (google 'intermittent reinforcement'. Unfortunately BPD are like children in many ways. They have maladaptive ways to deal with things they get triggered by (and they get triggered by a lot !). If a child has a tantrum it is counterproductive to give in and let your boundaries be crossed. Same with BPD.
My mum is BPD. I drew some boundaries and unfortunately she has chosen to give me the silent treatment for many months now. This means I don't get to see my FOO anymore. The bright side of this however is that I do not have to deal with the dysfunction anymore. My boundary is that I get treated respectfully.
Not communicating with you is your mother's choice. Also there you can have boundaries. You can choose to keep away until she resumes contact. Or you can send her an email trying to reestablish contact. Or phone her. You can also decide that not having contact at all is the best way for you to live your life. And to keep your sanity. The wonderful thing here is that you are an adult now. You are not a child anymore, and you are *free* to choose sanity. Having cancer is *not* an excuse for making people's lives miserable. It is very unfortunate for your mother to have cancer, but this should not be the issue here. The issue is that you want to be treated respectfully. This is the main issue. A side-issue to that, an issue that complicates the main issue, is the fact your mother has cancer.
Children of BPD are raised with guilt always being around us. We were groomed to feel guilty whenever our mothers didn't feel good (which was pretty much all of the time). This is not how it's supposed to be. I have a daughter now and I would never wish her to feel guilty because of me feeling bad. I am responsible for my own emotions.
If one day I'd have cancer and god forbid I would treat my child badly, I would want her to tell me to stop, or if I didn't, to keep away from me. I think this is how we should feel when we love someone.
There is a lot of info on the right, also info about FOG (fear/obligation/guilt). Maybe you can take a look.
And I am SURE she is making me out to be Satan's child for all her friends and family).
This bothers me because I really care what people think about me. I am a bit too hypersentive to others actions and feelings.
I understand this very well. Being hypersensitive to others actions and feelings is something that again has been installed in us when we were a child.
My mother is talking bad about me too. Luckily not to a lot of people (she doesn't have friends, so that limits the options ;-)). When I hear about it, I choose to simply tell people : "look, when I was younger, things happened in my FOO. It's very personal, I do not want to talk about it and I wish you don't interfere." I had to tell this to my aunt. It's very clear that she chooses sides with my mum, but so be it. I still have a rather good relationship with my aunt (the only family I have left except my daughter, so I'm glad). But if I did not, I would dig with it too. My mother speaks bad about me, it's not my choice, it's hers. I cannot do anything about it. And when a mother speaks bad of her own child, it says more about her, than about the child. If people take sides and start to avoid me because of it, I'd assume those people are not worth my time or energy. Some things we just cannot change.
Is your partner aware of the dynamics of your mother and the people around her ? Is it something you both can talk about together ?