Should I quit my job, or try to wait and see if things get better?

So back in July i took a position at my workplace (I'm an LPN at a nursing home) In which I have more responsibility, and am basically doing some of the office nurse work one day per week as well as doing all of the skin measurements weekly (basically I am the skin/treatment nurse every monday) I began this job the 2nd week in july with only one week of minimal on the job training...i was never really taught what to do in this position, just got the basics. the facility i work at did not have a policy and procedure manual for me to reference. In the beginning of September we had our state survey and we got deficiencies because of some of the things I was not taught and did not know to do, but i was the one held responsible for these. now i am under a microscope as the state will be back soon to check and make sure things are being correctly now, well today a sheet proving that i had measured a wound every ( and proved to the state surveyors that i WAS doing my job) came up missing out of a three ring binder that everyone in the facility has access to, immediately i was the one held responsible for this being missing. i was basically told i HAD to find it or i would be in huge trouble when the state came back to check on our deficiencies. eventually i did find this missing paper and I WAS NOT the person who misplaced it, I don't feel that the administration was in any way fair to me in saying it was my fault before knowing the facts. Anymore i just dread going to work, i am in a bad mood all the time, and today i just broke down and bawled my eyes out in the med room in the middle of my shift, i cringe when my phone rings thinking it may be my job. What should i do, any advice should i stick it out and try to work with my DON and the administration to get past all of this or should i just pack it up and move along...any constructive advice would be much appreciated.