Anxiety attack

Ema

So, I'm a freshman in college and I have anxiety and IBS. My IBS causes my intestines to make noise and because of that my anxiety has been going insane. I have my first exam tomorrow, after about 5 monts of no exams and I'm really anxious about it. Whenever the room is silent I get a panic attack (heart beating fast, feels like a mist has set on my brain and I can't control my body and can't calm down) because I'm so scared of my stomach making a loud noise in a silent room with so many people. Changing my diet has helped but my anxiety won't budge no matter what and I'm scared I'll spend the entire exam in a panic attack. I've tried breathing exercises, grounding, meditation, different sitting poses etc. but nothing seems to help my anxiety. It's like all of my "calm" goes away the second I sit down. I can hardly concentrate on anything else and I'm not allowed to skip this exam because it's mandatory. I'm currently in the middle of doing some tests to determine my health all over and I'm going to speak to my doctor about the anxiety but I won't be able to see her before Thursday and I just need something to help me get trough 40 minutes of the exam. Does anyone have any tips?