Hi I'm a 21yo female, I think I'm autistic...

I've been really struggling for years now with my mental health ect. I'm currently waiting for cognative behaviour therapy but the more and more I think about it, I really relate to a lot of symptoms of autism and its left me very confused and stressed and upset. 

My question is what's the likely hood of getting diognosed, because I honestly need help in more ways than I can express. It's very difficult trying to explain things to my doctor so I don't even know how to go about it. 

So autism runs in my family but usually just on the male side, hence why I figured it might be worth bringing up. 2 out of 3 of my brothers are on the higher end of the scale, requiring full time support, with my other brother on the lower end of the scale, being adopted with me. 

My symptoms include

Extreme stress in new environments and social situations

Struggling with expression of feelings 

I bang my head on things backwards when I get stressed out, it's literally something I cant control and have had to ring an ambulance because I gave myself a concussion. 

Turning 21 I've been taught everything properly on how to live basically but there's days where I just don't understand it at all. 

I don't understand a lot of human interactions and get very stressed when things don't go to plan in a social situation

Also not understanding a lot has got me into trouble alot as a kid, I also came to the realisation that I was sexually assaulted as a teen because I didn't understand it was wrong. Someone in school made fun of me for being a virgin, I just didn't understand... 

This has been so painful to write, I appreciate any advice because I'm at a total loss now. Thanks in advance