medication error

I was a LPN for 10 years and a RN for almost 2 years..I started a new job this week at a LTC facility. I shadowing a nurse for two days, and on day three I got to do a med pass while the nurse hovered and offered assistance as needed. Well I accidentally gave a PRN medication of 10mg valium to the patient instead of the scheduled 2mg valium, the error was discovered during our med count and we reported it to our DON, the DON told the nurse to call the Dr., get vitals, and chart on the patient. I was the called to the DON office who told me that she was doing a review of my work so far, she said that this mistake must never happen again. After I left work for the day I received a phone call from the office manager who said that I was taken off the schedule and that I would get a call next week, I called the DON back and asked what was going on and she told me that my review has to be discussed with the CEO and administrator, and after the meeting I will be called about further scheduling....Does anyone think that I'm about to fired for this med error, I'm really nervous