Off topic for a moment, but need advice!!

Hi

This is slightly off topic for a moment but heck i need some advice.
OK Long story short, i was brought up by my wonderful grandparents who have both now sadly died, my grandad passed away in May this year from a heart attack......i have never really got along with my real mother (thier daughter), but when my grandad was dying in hospital i confronted her as to why she had not called me when i was diagnosed with breast cancer.....she replied (in her words) "i don't care if you die from this", also she called my son, again in her words "a little black b****rd"...now, my son is half Portugese but even if he were half water buffalo he is still my son and HER grandson!!!
Anyway, today i received a court order ordering me to stay away from her, otherwise i could face a prison sentence.
I cannot believe anybody would stoop so low, my husband called her to confront her with regards to her comments and i admit some rather colourful words were used but can you believe any mother would be this way to her own daughter??
I believe her husband (NOT my father) is behind all of this, but i am so upset, i really need my mum right now and she just pretends it's all my fault we don't get along.
Since having being diagnosed with breast cancer i don't need this kind of grief in my life, i try to ignore it but deep down i'm hurting....i am so angry at the moment i just want to go round there and smash her teeth in, but i know that's not the thing to do.
How do i deal with this? how can anyone be so cruel?
I hope you are all well, sorry for changing the subject here but i need some opinions.
Love
Nikki x x