First death

Refer your managers' questions to your preceptor. They were training you when the patient passed. Did you ask your preceptor if the manager is also questioning  her?  It sounds like there may be special circumstances.

This is your first  patient death. It will effect you. Going to be a rough first day on your own.  It will get easier, I promise.

Well I'm sorry that this is what you are getting (from your manager) with your first death experience, which is enough to process in and of itself.

As far as a nurse's first experience with a patient dying, that is something that we have to process, it isn't instantaneous understanding and acceptance and moving on for most nurses, I don't think. It's one of the many things that mentally moves one from their original/immature thoughts about nursing and wanting to be a nurse....to the acceptance and actual knowledge of what all nursing entails. From my perspective I think it's fair to say these experiences change you as a nurse and as a person. Kind of like growing up, in a way. It's okay to be bothered or very contemplative or...whatever you feel at first. If a nurse is struggling in a way they don't think is normal, they would want to reach out to their Employee Assistance Program (EAP), talk to a trusted coworker or manager.

Your manager should not be bombarding you and should not be contacting you about this outside of work channels--meaning communications should involve neither your personal time nor your personal devices, and you should not engage with them about it outside of appropriate channels.

You'll be okay.

Just know you are a very good nurse for caring. This part of nursing is not what you signed up for but sometimes you are put in circumstances that you don't accept, approve of, want, or ask for. When you are new, you don't know how to advocate for yourself or safe patient staffing. Somewhere along the administrative chain, having 6 patients, all having acute needs, one or two nurses cannot do it all. You were being trained. The only thing you can do is learn from the experience, become strong in your practice, for example DEMAND the CNA's do their jobs, their vitals, (if you even have help, which that is an administrative problem for not providing enough support staff or quality staff) have the nurses before you have their patients in proper order, in proper position, all safety measures in place before you take the patient. This is YOUR practice and let them see you for that. It will be your first shift after the incident, do as you normally do, take care of your patients. Don't be intimidated by your managers or coworkers. Just go on about your normal business and take care of your patients. 

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!!