Early I asked for info but I am just going to go with YTA.

You brought your iPad to a class and your drew your favourite character. Your drawing probably didn't seem wrong to you but it's clear your teacher had an issue with it. She took your iPad from you and then you decided to take it back and continue drawing. This is not the right response to have. You then grabbed your things and yelled at the teacher and it is not okay at all to yell at the teacher.

The way you've written this story as well paints you to be the victim and your teacher to be a bully.

In this you've said the following: I am struggling with depression, I've been diagnosed with ADHD and Autisim.

meanwhile you've used the following words to describe your teacher: She ripped it out of my hands. She yelled at me to the point of my ears bleeding. She made me think what I was drawing was nsfw.

I have a feeling there is a middle ground here and it didn't involve her ripping your device away from you or yelling to the point of ears bleeding.

Also the last thing you said is nothing but entitlement.

I should’ve been allowed to be on my iPad because I finished the work.