Coping with the death of a patient is part of the process of growing as a nurse. There is no way to get prepared for it ahead of time. The fact that you care deeply is going to help you sort this out and while a patient's death won't (and should not) ever be "run of the mill" you will find your own way to put it in perspective, to offer a prayer if that's what you do, and to offer kindness and condolence to the family if you can.
Identify and reach out for support and insight from your "Short List" of nurse colleagues who are caring, trustworthy AND know what they are talking about.
Finally as for the questions from management, this will always occur. In so many situations you will see what looks like panic from management, sometimes nurses seem to just like the drama, always everyone in the hospital will CYA. You should CYA too, but know that: as long as you 1. did what you know you are supposed to do, 2. asked your preceptor for help and instruction, 3. kept the preceptor informed and involved and 4.documented ALL OF IT, this management panic will pass without incident. The next event will arise and pass. Learn from all of it and Best of luck!!