So I always record myself when playing, and act like the camera's a person? Idk. I had mega performance anxiety to the point where I almost passed out onstage. You could try playing in front of like your pet or your parents (provided you live with them) or a close friend or something. And I'm sure you sound better than you think you do! I envy piano players.
I'm guessing just forcing yourself to do it wouldn't work, but it worked for me so you never know. Good luck! You'll do great, I'm sure. :D

Setting up a camera while practicing can be a good way to mimic the feeling of an audience if the area you are in is in lock down.

If your exam happen on an actual stage, the difference of lighting between it and the vewing area will actualy create a visual forth wall that can be used to forget about the public. If not, try to focus on your music sheat. If you absolutely nead to look at them, do not look at their faces. Instead, focus on a point behind them at about shoulder height, unless you are higher then them in witch case the point should be a bit higher at about ears level. ^-^

put a blindfold on so u dont see the cam

Thank you for the suggestion! ;v;

I tried using my computer's voice recorder. Turns out, some of my pieces sounds rushed lol. I envy other piano players as it looks like they look so natural at preforming and they don't mess up T_T

I also suspect that my left hand's too weak.. more to practice xD

I tried that, and I'll continue doing it for the remaining days ^.^ Thanks!

I'm not sure how I managed to do my previous exam 3 years ago lol. I keep my eyes on my hands, although that sometimes makes me mess up, because then I end up playing on a spot I thought the notes were. xD

(Not sure if this is a reasonable response, since I'm rushing haha)

I would love to do that, but unfortunately I need to look at my hands while playing! :)

wear a hat and just look at ur keys the hat will block out the camrea/people