It helped me to imagine how RELIEVED I would be afterwards!
Also, to trust my intuition and ask 'what am I going to be asked' and open the book at random. Often, I zoned into parts that I was asked later. I learnt everything, but not everything so in depth, this method helped.
Also, I heard/read that everything we lever hear/read/experience is remembered by our subconsciousness, you just need to recall it. So I asked my subconsciousness to give me the right answer, as silly as this may sound. That it would 'swim out' for me, and very often it did...
At one exam I also told the professor that I studied, 'It's on the tip of my tongue, can't remember it...' and he was sympathetic. It helped that I knew a lot about some other things.
Maybe you can even tell in advance that you're very nervous about it (or whatever you are comfortable saying) and hopefully they would be sympathetic with you?
You can always re-take an exam, the thought of this helped me too!
French is such a fascinating language! Maybe you can imagine how good it will be to talk to French people in France, go to a bakery and order some goods, dunno... It always helped me to imagine the culture, so your learning has a purpose... (not just exam by itself)
Good luck & fingers crossed!