Please note: the answer has been considerably improved since this question was posted here is the link to the version this question was referring to: https://workplace.stackexchange.com/revisions/22076/1
Since no one else has stated it yet - this situation reads like your manager is laying the groundwork to fire you. In your position, I would expect that in 30 days, you'll be called into your manager's office and will be fired. Yes, even if you improve, and no, there's probably nothing you can do at this point to change that. At the very least, your manager has already made up his mind that he wants to fire you, and will seize any excuse to do so.
As such, the only option you have is to get a new job, before you lose this one. (It's often said that the best reference for a job is currently having one, so if you wait until after you're fired, you will find it substantially more difficult to get another position.)
The question asks basically what can the OP do to save his job because quitting(and presumably getting fired) is not an option for him.
The answer says there is nothing you can do, and jumps to the conclusion that the manager is a dishonest person out to get him and there is nothing the OP can do. The question predictably hit the hot list and the lemmings that came along quickly decided they liked this defeatist answer that is not helpful, and really shows no effort to back it up.
I would also point out that dispite the posters claim: "Since no one else has stated it yet"... an answer that was posted several hours earlier includes this possibility, while providing a possible strategy for the op saving his job.
Here is the truth of your situation. You have one foot out the door, and if your manager was allowed to, you would probably already be gone. Your manager went through a lot of work to get to this point. His expectations for you are low and he is not likely to give you any slack at this point.
He has no intention of helping you, the point of this exercise is to either forge you into a quality employee or break you. You will come through this either stronger, and with a better understanding between the 2 of you what the expectations are, or you will be gone. If he gives you an impossible action item at your meeting tomorrow just realize that is his out if you step out of line. It is the proverbial axe over your neck. It is there to make you feel uncomfortable and to remind you that your future with the company is in his hands.