Ptsd from death

I already have ptsd but I experienced a more traumatic event. TW death. My mom died in my arms. She had cancer, got a brain infection from surgery, then had a stroke, was on life support, and ultimately got taken off. I was in the room when they did it. I held her until she was cold. They almost had to pry me off her to get time of death. My grandma chose a song to play in the OR before moms organ donation surgery. She chose Scars in Heaven. I have flashbacks everytime i hear that song. I dont even know the words but i always instantly recognize it then all i can see is mom lifeless and feel her skin on my hands.