There's a massive backstory to this that's too long to post so I'll try to keep this as short as possible happy to answer any questions that won't be outing and I have changed some details to avoid being outing as I don't know if my sisters or other family are on MN.
I've had a difficult relationship with my mum since she left my dad over 20 years ago due to domestic violence. Whilst she did the right thing in leaving him she also changed and not for the good in my opinion. She basically left me and my older middle sister (my eldest sister stayed with our dad) to fend for ourselves and my sister ended up being a surrogate mum to me as our mum was always out drinking in pubs until midnight or later. My mum whenever this gets brought up minimises it and says she went a bit off the rails when to me she basically checked out of parenting and did the bare basics i.e. we were fed and clothed and physically safe but were traumatised due to what my dad did and she never once thought about our emotional needs or the trauma we also suffered and my sister was the one who took on the parent role to me which caused issues in our relationship but we've managed to sort that out and do have a much better relationship now we are adults.
My mum has always played favourites with me and my older sisters examples they get treated with respect, like adults, never get called out on any bad behaviour and can do no wrong and my my mum will always excuse it. But with me my mum constantly criticises, judges and nit picks at me for any slight thing and has done for years and when I stand up for myself turns on me and says I pick fights, I'm wrong and need to change my attitude. My mum would then tell my sisters and other family members she doesn't know why I am so angry at her and what she has done wrong leaving out her part in our many bust ups denies it or says she doesn't remember so it never happened.
Now to latest problem. We had an argument about a month ago she started criticising me over something I got for her when I was shopping and how it wasn't enough I should have bought 2 of said item (she asked for only one of those items) I was already feeling fed up as I constantly have to listen to her complaining so I asked her why she always complains and her constant negativity is getting me down she of course turned on me told me I was getting upset/annoyed over nothing and she was just saying I tried staying calm to discuss it but she told me to fuck off and put the phone down. I was pisssd off and sent her a text basically saying she's nasty and this why I speak to her badly. We didn't speak for weeks no apology from her (she never apologises unless someone else tells her she is wrong) but she then got in touch to ask if I was still looking after her dog and cats whilst she was on holiday which I did for 2 weeks.
She got back 3 days ago and within minutes was checking things and commenting on housework I hadn't done and then asked me if I had taken some money she left in the draw in her coffee table. I hadn't even known it was there in the first place because I don't go down other people's things and I would never take something that doesn't belong to me. I am really pissed off about this because I feel she was basically accusing me of thieving and whilst I have always felt she hates me and has a low opinion of me I never would have imagined she thought I was capable of stealing money!
I have now had enough of her and want to go NC but have always been reluctant because I'm already NC with my dad and she is the only parent I have and I've always felt bad because I know what a hard life she has had but I'm now seeing she isn't a victim like I always thought. I do a lot for her and she does for me but she always dismisses what I do and sometimes doesn't even remember the things I've done to help her but she can recall everything she has done for me.
So from reading all this am I right to just cut her off and not bother anymore? I don't plan to confront her because there is no point she will deny every horrible thing she has said and done to me over the years so I don't want to waste my time.