AIBU to think my mum is making life difficult?

[Twinlife2]

Bit of context so please excuse the long post. My mum and I have a close relationship. To her credit she's dependable and good in a crisis. She looks after my daughters once a week while I am at work. However, I've bore the brunt of her anger and vicious sarcasm on more than one occasion. She seems incapable of acknowledging anyone else's feelings or point of view and she's definitely never apologised for anything.
Two big examples of this spring to mind. When I was in my early twenties, I was seeing an older man. She never met him but disapproved because she thought he was married (he was separated). When she found out, she assaulted me. Physically and verbally. I moved out the next day to live with my Grandma. We hardly spoke for four years and the more she isolated me, the closer it pushed me and the older boyfriend. Eventually, it fizzled out and we got back on good terms. We've never really spoke about what she did, I just buried it and forgave her. The next big occasion was just after having my girls. I really struggled with post-natal depression and the lockdown hit and I was completely lost. She basically told me that it wasn't PND and that I had to pull myself together to look after my beautiful girls. Her being so dismissive exacerbated how I felt and it made me even more distrustful of how she handles other people's feeling. She had her hip replaced earlier this year and she'd ring me up and cry, saying she was struggling with the mental impact of the surgery as well as the physical ramifications.
I avoid inviting her and my step-dad round if I know my in-laws will be there because she makes things really awkward. One Christmas Eve, we had a little get together with both sides of the family. My MIL made a throw away comment about how my DH would love to take paternity leave (I was even pregnant at this point) and she stormed out and didn't speak to me for weeks afterwards. I had no idea why until I called her and she was so angry that MIL suggested that because she thought she'd never see her grandchild. She always likes a drama at Christmas!
My brother and I suspect she drinks too much and this doesn't help her mood one bit. She's a nasty drunk and after 5pm I won't call her because I know she'll have had a drink.
We're not on speaking terms after she mimicked me over something trivial and I've reached my threshold. It's always me that makes the first move to make amends even though I feel I wasn't in the wrong to begin with just to try and preserve some sort of a relationship with her. This has just enabled her to do and say whatever she likes to me.
AIBU to have no clue how to move forward with this? Any advice is much appreciated!

She doesn't sound dependable or good in a crisis at all - look how she treated you went you reacted out for support when you had pnd! I also won't consider a close relationship one where I had been assaulted, hardly spoken to for years, my pnd belittled, my special days deliberately ruined by self obsessed dramas, where I'm frequently stonewalled as punishment and where I can't phone after 5pm because she's nasty drunk.

She sounds self obsessed and incapable of seeing you are not an extension of her. You had the wrong type of boyfriend, she assaulted you and then isolated you. You had the 'audacity' to need her support, instead of you supporting her, she belittled you. She creates dramas and ruins Christmas because it wasn't all about her.

Perhaps looking at the stately homes threads will open your eyes to how dysfunctional she is and how the 'norm' of this relationship isn't normal at all.

Short blunt version: she's a bitch, tell her to fuck off and don't feel guilty about it!! She's never going to be capable of having an even vaguely decent relationship with you and your dc so why bother!

Keep your children away from this toxic nightmare. She will never change, op, and she will soon be directly her wrath at your kids.

She sounds toxic.
Do you think she could be a narcissist? She sounds like one.
You are always at the whim of her ever changing moods and emotions. This isn't normal behavior at all. I've been here with my MIL with her being helpful, and yet a deeply dysfunctional and emotionally immature woman who has caused me problems for many years.

I have nothing at all to do with MIL now and I feel free. My own sister has narcissistic traits too, so I have cut her off. Life feels better for it. I do feel for my children because we have such a small family of people that we do see, but these toxic sorts aren't worthy of giving anything- they just make everything anout them

There's a book you can read on toxic parents which will help you out of this pattern. You don't have to put up with people making you feel bad just because you're related.

She is a nasty abusive drunk that has assaulted you?

What on earth are you thinking of having her anywhere near your children?

Do NOT contact her again.

Seek out some counselling support for yourself.

She is a toxic poisonous presence in your life.

Cut her out and protect your children.

From experience myself, she's very toxic and doesn't deserve a relationship with you. She's clearly making you unhappy and doesn't care by her attitude. I cut my mum off years ago and haven't looked back. She won't change and neither will your mum x

Try a carers assessment from social services. You can then explain all that is happening and then you will have an organisation involved who may suggest help from GP/mental health services. Your GP is likely aware anyway that she's going to hospital a lot wirh nothing found. I think at this point you do need interventions x