Struggling at school

Hello i was recently diagnosed with autism and I'm in year 10 of school and my year head said I'm not allowed to wear my ear defenders in lessons because "I'm year 10 and i should be listening" she also said "others in the school with them dont wear them in class so" and also said she would take them of me if i wear them in lesson again. at the end of the day she said ill only be using them to ignore the teacher she was smiling but i cant tell if she was joking or not. Also today my geography teacher told me to take them of she had not even started the lesson yet and was sorting test papers out, and the classroom was loud at the time. i took them of and the noise caused me to cry instantly and it just kept getting worse and i ended up hitting my head and people ended up laughing at me and pointing out i was crying. then the assistant teacher that helps me and my friend came in i was still in this state. and i ended up hitting myself loads of times again she offered to take me outside but i didn't say anything. today i told my counsellor what happened and she said she will get a plan in place and a few other things. also she handed test papers out and said i got 0 and the class was quiet and people was laughing at me again. and she wrote on the test not even tried. on the day of the test i didnt understand a single question and ended up crying. i feel like no one understands me so i remember coming on this website before for information on autism before so i decided to write something. does anyone have any advice. sorry if this makes no sense