Wondering about not being in a room full of people during the LC

So basically I am in 5th year and I have really began to notice how I can’t concentrate and get districted by everything (everybody) around me especially during tests and it makes me forget the stuff I’ve learned and I end up doing way worse on tests even though I know how to answer them. I also panicked a bit during the junior cert because of all the noises and stuff from other people and messed up some answers but thankfully I did pass everything The school guidance counsellor has been absent this week so I could not ask him about this but how would I go about not being in a room full of people for the LC and instead being in a different room with less people. I am also waiting for an assessment of autism which I’ve already been told I a very high probability of being diagnosed if that can help with anything?