Thank you! It's very hard, because it's common to find support when it comes to partners or children, but less so when it involves parents.
My mum got diagnosed with ASD quite recently actually, despite her having higher support needs than I do. She has pretty frequent meltdowns, can't do employment or finances, isn't able to read and write that well and has no concept of boundaries. Because of this, she has been in abusive situations all her life. She now has a carer. Our relationship is really strained; I'm trying to be no/low contact with her (since earlier this year) for a whole host of reasons, but she talks to my in-laws and friends independently from me and it makes it difficult, especially because my MIL will ask about her and I awkwardly have to say that don't know.
Part of the problem is just that she doesn't get things. And now she's bombarding me with messages regularly about how it hurts her so much that I am mad at her and how she loves me and the only limiting factor to her love is me ignoring her. My mum is autistic, but she's also a controlling, emotionally immature person who loves to be center of the universe, and it's hard for me to judge where one ends and the other begins. We had an argument earlier this year because she refused to give back one of my belongings, after which she gave me the silent treatment for 3 days straight + told DH that she was done with me. As soon as she's on the way home she texts me to say she felt uncomfortable with the 'atmosphere' and asked whether I was mad at her because I was acting weird... Like her memory of the incident was suddenly completely gone. When I reminded her she said she didn't quite get it but she was sorry and couldn't help her behaviour because she's autistic, and that my 
reaction to her behaviour (which she now suddenly remembered...) reminded her of my abusive father (who was just as abusive to me).
Then a few days later she messaged me saying she's hurt because she gets the vibe that I sometimes wish I had a different mum. I have to seriously bite my tongue because whenever my mum couldn't cope with whatever when I was a child, her reaction would be to tell me she was sending me to a children's home or wondering why I wouldn't just be like [insert other child]. And her not coping included normal things children do..such as playing a little messy with water, or wanting to get up before 10am on weekends (pre teenage phase of course).
I really want to tell her that yes, I do wish I had a different mum at times, but that would probably not even do anything other than needlessly upset her, so I'm stuck with all my feelings and all my history without ever having the ability to make her understand, and it really sucks.
Sorry for the rant, today is not a good day. I don't really know where to go for support with parents because there's no thread - the stately homes one kind of assumes your parents are NT. It's a little different when they are not, though probably no less stressful. My mum doesn't always understand normal dynamics. For a really basic example, she calls my MIL 'mum' and calls FIL 'dad' at times, even though she's older than them and they are my in-laws. Similarly she'll engage with my friends in a way that suggests she sees them as her friends, rather than her DDs friends. It's not malicious, but it's one of the less problematic ways I can explain she doesn't always understand social structure and hierarchy. It's not as though she constantly wants to hang out with my friends or ILs, but she doesn't seem to get how old she is in comparison to them or what normal ways to address them or interact with them should be. I don't really care about this, but just using it to illustrate her level of understanding.