I have never been with someone who was dying/died by suicide. I have, however, been with dozens ? while they died in the ICU where I worked as an RN.
The circumstances were each unique. Some died during a full code. Others were disconnected from life support and just slipped away. Some were revived for a while, then coded again. Those who died after being coded were the most traumatic. A full code can be a very violent thing.
It was never like on TV where one minute they were awake and talking and the next they were dead, mostly because we had them drugged for various reasons. But once they were gone, you could see the absolute lack of animation on their faces. Even during a code, you could see that and know the resuscitation attempts would fail because they were already gone.
Three stand out in my memory. One was an older woman who was in a car crash with her husband. He was DOA. She was bleeding profusely but her religion prohibited a blood transfusion. Her brain was so damaged from lack of oxygen, she was in a vegetative state. Her son and daughter in law came daily to spend time with her. We finally disconnected life support after weeks and she passed peacefully with them at her side. They were so loving to her. I will never forget them.
Second was an elderly woman who had a massive stroke. I knew her time was short. Never had a single visitor. I called the family contact and told him that she was dying and if he wanted to be there, he needed to come right away. He said, "Call me when she's dead" and hung up. I was shocked. I went into her room, held her hand, spoke softly to her, and was with her when her heart stopped. (She was unconscious the entire time in our unit.) I was not going to let her die alone.
The third was an 18 year old girl, car crash. She, too, was a member of the no-blood-transfusion religion. Again, the lack of oxygen to her brain caused complete brain shutdown. She was on full life support. Her pastor came in with a copy of a contract she had signed, stating no blood transfusion. We respected that. The pastor told me he had never signed one. I told him maybe he had better do that. She was declared brain dead, her parents wanted to donate her organs. There was a meeting with them and the organ donor people (and me). Everything was explained. I sat next to her father, holding his hand, when he asked what would happen next. He was told that first they would do a blood transfusion to perfuse her organs and prepare for the harvest. He looked at me and asked, "They can't give her blood to save her life but they can give it after she is dead??" I just looked at him and nodded. 18 years old. Btw, her parents were not members of that religion.
None of us who worked there ever "got used to" it. I was a mentor and trainer for new nurses and told them, "If you can watch this without it touching your heart, you need to not be a nurse."
After seven years in that unit, I am not afraid of dying. I am sometimes more afraid of living.