I struggle to explain autism to my mother

Hi ! I am a 20 years old student, and I was diagnosed with autism a week ago after months of burnout. The title of this post is quite evocative, but I am writing this to seek some advice regarding explaining autism to people, and especially to my mum.

Throughout my life, I have done everything I could to never appear weird, never ask for any kind of help (like even asking for salt at the table), never talk about my problems, etc. And now that my autism is too “real” to ignore, I often have to explain my needs and accept accommodations. However, my habit of not existing in the eye of others has left deep difficulties to do those things. Moreover, my mother is a very insecure person who has always “needed” me to kind of be her neutral and mature therapist, in the sense that she has always shared too much things with me, but she also needs a lot of reassurance and she can’t stand it when I feel anything other than visible happiness. This has contributed a lot to me learning how to bury feelings and needs deep down inside of me, and now I reaaally struggle to get anything out. Everytime something is difficult for me, she just makes me feel guilty or ashamed, and her tone always makes me feel like I have to come up with arguments and explanations to reassure her while I am the one who is struggling. She likes to make me feel like a disappointment : her only child who was supposed to be perfect and repair everything she couldn’t do right, but who actually fails at everything and should be fixed.

Since last year, I have been trying to progressively communicate my needs to my mother, and she mostly responded by ignoring anything I said while hoping I would be wrong about my autism. Since I received my formal diagnosis, I really struggle to explain things to her because I feel like there is something inside of me that blocks any kind of need that I could express to her. When we are on the phone, everytime I try to talk about something that is difficult for me, I get a feeling inside my whole body that just tells me to lie and tell an explanation she can accept.

Also, I often feel like I really have some sort of “demand avoidance” when talking to people, because I know that I should put more words in my sentence or even start to say something, but my whole body is just like “It’s not worth it… Let’s just not say anything”. And it is very frustrating because I like to be understood, and I know that it is helpful to be understood, but in the end, I just… can’t.

Has anyone experienced this feeling ? What could I do about this ? :/