OMFG I have a maths exam in 13 hours and i'm so scared!!!!!!!!?

I always have this problem, i get so nervous that i'm going to fail. I've been working so hard and everybody agrees but when it comes to the exam because it's a CORE 2 exam the questions are phrased strangely and sometimes after reading through them i have a heart attack and my brain explodes (meaning it's quite hard to think logically) but with the core 1 exam I read through it and thought wow this looks hard but i can do this and used logical stufff. But this exam is so much harder to improvise with!!!!!!!! any advice?????