Welcome to the forum.
If you want to be friends, just tell me

I don't mind.
You say you have autism, well I say the people thinking themselves as 'normal' and calling other people who are diagnosed with autism ''retards'' are the autistic people.
(Not meaning to be offending here)
But one of 'points' are that autistic people cannot understand emotions or such. Then why would 'normal' people hurt you and try to 'downgrade' you?
...Exactly...
And what I think most autistic people are: Just normal (if there ever is such a thing as normal) people with a diffrent way of thinking and approaching things.
Anyways, let's just leave that behind.
As for teling your mum, well... If you want to, you can talk about it with her, one step at a time. For example: Showing anthro art (not yiff of course...) at first. And build it up from there.
I don't know your mother, and I am not telling you what to do, but I'm just giving advice and hope it will help

I've told people in my environment one person at a time (not all, lol)
I was a bit scared of their reactions at first, but I ignored that feeling.
'So what if they think I'm weird? Everyone is diffrent. If they're not willing to except, then that's fine by me.'
Also, the reaction was way less 'explosive' as I always would think it would be. They usually didn't mind if I was a furry.
I hope this helped you and sorry for the long text ^^;
Once again welcome.
And if you ever need to talk to someone: I'm always available
