I use to get the same thing, and still do sometimes. What helps me honestly, is closing my eyes, taking a few deep breaths and getting back to it. I do not stare at the clock, mores so just glance after I have finished a certain number of questions (5, 15, 20) to determine if I need to pick up my pace or if I am doing okay on time. If im not, I usually start to panic but will again close my eyes and take a few deep breaths.

Hope this helps, happy studying :)

how can i be sure my essay is perfect? i feel like there is always improvements to be made to matter what