Hi @Caz1973
Welcome though sorry you’ve reason to join us.
What you describe has been the experience of others seeking and offering help here.
The magnifying glass above access the search function - although finding IS hard - I’ve spent 10 mins & can’t find the posts I was going to direct you to 
Search for carer, abusive, “personality change” “mum/dad/partner had…” etc (probably best not all at once!) and when you find a thread started by a fellow community member
It’s often useful to then read other threads they created which can be done by:
<--- click here to open (close) step by step instructions
Clicking on their picture/ initial opens their thumbnail,
Clicking the thumbnail picture opens their Profile
And then their Activity ( three horizontal lines) and topics
And then their Posts will allow you to see conversations they have started.
While these might not be focused on your need they will give you a broad background with a specific nugget every now and again.
Emotional changes happen. They aren’t necessarily permeant.
You need to look after your self as #1 priority since you’re the foundation on which everything else rests - so look for local support groups Eg here and here, and ask ageUK, citizens advice and the stroke association helpline for other agencies and ask the agencies what to support they can give you. Ask SA helpline to sign you up to the Here For You carers 8-week support program.
Most of those above sources might also help you with your mum But I’d also add adult social services and your GP and maybe a neuropsychology referral. Her behaviour might be directly affected by the stroke’ damage and may evolve as recovery happen. It also will have a component that is behavioural or reactionary to having been traumatised and here counselling might help. Also you should be aware of 40 things because some of them might be helpful
Others will be along to say hello and often have very valuable advice that would never occur to me
The more detail you give us the more likely it is we can direct you to useful sources.
use this as a place to unburden your need for a cathartic rant as well as ask advice and celebration when you get progress. With all been there in one way or another 
Caio
Simon
Ps You might also find the welcome post helpful