Oh man, exam stress is really torturous, on your body, mind, well being, it just affect everything, particularly if you're unprepared.
It's easy to feel like your exams are over and you start relaxing towards the end, because there's just one or two exams left, make sure you keep your eye on the ball till the end
My exams are over now, but when I was doing them and experiencing the stress, I tried to change my perspective, at the time I felt doomed because I wasn't as prepared and like giving up, so before I went to bed every night, just to calm myself on the inside, I tried talking it out, i'd tell myself things like, i'm capable of doing these exams otherwise I wouldn't have been allowed to take them, and that i'm sure I can answer things better than I think I can, but if I do fail, it won't be the end of the world, so many people have failed at these things before me, and i'm sure they were still alive and breathing afterwards, and whatever happens, I will always find a way out, it's not like i'm going to end up in a gutter, but even if I do, there's always some way to get out of it, and there's always help available, family, friends etc.
These little self talks would help a little, but even then i'd still feel the stress, my sleep wasn't quality, my mind was blowing with all this information, I felt like I wasn't living
but remember it's just a (very) short term turmoil, and once you get through it in the loveliest way possible, you can breaaaathe
and don't forget to rest and give time to yourself or you certainly will exhaust yourself out