Okay, a bad performance review is the privilege of the employer. They can do this if they want to, however untrue or unjust it may be. You say you think they are trying to reduce staff. The answer to this is, do not let them force you out. Do not quit your job until you have another one. Suggestion: take this situation as a hint that you probably need to be looking for another job.
It is always better to be fired from a job than to walk off due to hurt feelings right now, proud and strong, and also without a job and most likely without unemployment benefits. They'd like to see this happen, but it wouldn't be good for you. If they actually have to fire you to get rid of you, they have to show the unemployment system they had a valid misconduct reason to do so or you would qualify for unemployment benefits if they couldn't do so. And this would cost them money.
Be sure that you pay attention and accept any valid criticism that was given during this review. In other words, if they said you were doing x, y, or z that you should not have been doing, don't do it any more. If they said your productivity was too low, try very diligently to do your best. Then eventually, if they do (which they usually do not) get around to actually firing you for poor performance, you will be able to say, very clearly, "I was doing my job to the best of my ability. I did not do x, y, or z after I was told not to do it any more in the performance review."
But if it is a bad evil rotten place to work, and they are liars, cheaters, discriminators, and everything else bad, your only recourse is still to find another job elsewhere. It is an at will state, they can do whatever they want to, pretty much, even up to making up bad reviews.
Find a new and hopefully better job. I strongly suggest that you do this BEFORE you quit the job you have now, as they would not be likely to give you unemployment approval if you quit the job, even if you were given a poor review unjustly.
