What is the best approach?

Ever since I was little I have always been a strange kid. It was never in a bad way I js normally understood things faster but it was always in my own way. A while ago I had an encounter with my dad, who I have never had a good relationship with and we were talking about school. I remember him yelling and getting over a simple mistake I had made. I believe that he had used a different word from the one I was using (ex. Test instead of quiz) and in my brain I didn’t understand. This has happened quite often since I was little. I always put it off as he was having a bad day or js said others have it worse. He would always be rude and ask oh are you getting bullied, but it was never genuine. The thing was that was just how my brain worked. 

He would also do things like this with how my tone or attitude was. He would get really upset when I didn’t even know i had a different tone. The problem wasn’t that he got upset it was that he wouldn’t try to help me. He would just get upset as if it would automatically make me know how to fix my tone. 

One of the other things that would always happen that upset me a lot was that even after he would get mad he would make a joke and pretend that nothing was wrong. And as a kid i normally would easily laugh at anything and now that i think about it, it kind of feels toxic. I have so few memories from my childhood and i feel like he took them away from me.

My main point with all of this is what has to do with the title. I believe that I’m autistic (the above stories being some explains of why I think so) and my mom who I have a better relationship with, I don’t know how to tell her. My dad has made me afraid to share my feelings with someone I know and worries me that things could be said about. How should I try to approach this?