Take a few deep breaths. Contemplate your place in the universe. Stop taking caffeine. You are going to be okay.
If there is any way you can hire an attorney (borrow the money, etc.) you should do it.
You have the right to avoid writing self-incriminating statements on the internet.
More people are killed by "unload" guns than you can imagine. However, speak with your attorney. They will know the range of possible outcomes. You need an attorney who knows the judge and the prosecutor in the court in which your case is set. The PD, if they’ve been there a while, will know what is what. Stop “freaking out” it never helps and only hinders. Trust your PD or get the money together to hire someone you trust. Gun cases require a skilled, experienced, and knowledgeable criminal defense attorney. I’ve done two in the last month, and getting a good outcome takes time and skill. Packaging yourself is important. The DA goes in on each case only knowing what is in the police reports. Your attorney has to show you in a “good” light, i.e. packaging.
Now, frankly, I don’t know the facts, the court, the DA, the clerk, the bailiff, or even the janitor; so, my specific advice would be more than useless. However, the advice of your PD, they would know the court, the DA, the clerk, the bailiff, and even the janitor, is a different matter altogether. Go to your meeting with the PD. And, please be respectful of their time. They work very hard and don't earn the "big bucks."
Given the nature of the offense, even a misdemeanor conviction might affect your ability to remain a nurse, at least in AZ. Please see a competent criminal defense attorney immediately, and make certain that he/she is either (1) versed in the state regulations for the nursing board or (2) will become versed in those regulations. If you are to keep your license, you must be very careful about either going to trial or pleading to a lesser offense.