How can someone fight a FG article 15?

I was on a 24 hour and decided to take a 40 min nap (set my alarm) in place of getting dinner. I had my runner watching over until my break was over. Search at major in for a surgeon are pushing for a field great article 15, wanting to take away my e6 to an e5 for “sleeping on duty” wasn’t even given a chance to explain that I was taking a nap in place of dinner because he went off on me calling me a POS and even mentioned my wife and kids. Got counseled and also told I was being recommended for a FG article 15.