How to deal with death?

So I'm a volunteer, to make this clear. I volunteered to get experience.

At one point, I cringed when I looked at the patient board and saw there was a do not resuscitate. Thankfully, I was rotated to the MIU before any other deaths happened.

I helped a CNA wash someone who died no more than 45 minutes later. Family was upset, and a guy walked out of their room and said, "Grandma has left the building". The memory is clear: I was walking down the hall when I heard this, and my eyes became wide with acknowledgement; immediately I walked into the nurse's station to escape, and remain stoic for the rest of the patients. Thank goodness I didn't have to help bag that one, my shift ended before that was necessary.

Nevertheless, I helped bag three other people; not observed but actively helped. On my first time I helped the ex-patient who was limp and not rigor, and when they were rolled over I suppressed a scream because I thought they became a zombie. Blame my generation. Nevertheless, the other times the nurse gave me the person's life story, or the nurses were solemn.

How does one deal with it? I'm still haunted, yet I am determined to be a nurse.