Ultimately, you need to seek and accept professional help. It's up to you to properly communicate what you are experiencing, and it is important to understand that nothing will get better without your engaging in the process honestly. I can't know one way or another if an ASD diagnosis is appropriate, but I can say that, if you feel like you need help, make sure you go out and get it.
I can feel your pain actually more than you'll know my moms bipolar and I was sent to a mental facility cause of being sexually abused when I just wanted help the staff cursed me out and wouldn't let me go home for 9 months to my family but you cannot give up no matter what happens and lying wont set you free the truth will I promise you even if your mom feels a little hurt only good will come from it let it out and strive to only do good things in your life and you'll be closer to your mom
Get her in a room by herself tell her I feel bad about what I did it will be worth your while