Do you have any friends in that lecture? Would it be possible for them to help you out of the room, place you somewhere safe and then get you some food? Also, do you have access to water? It can help immensely to just sip on some! If not, wait for the other students to leave the room, and then ask your teacher for some help.

hey anon thanks a lot for your concern, i only saw this message now and i was fine in the end but i really appreciate this 🙂