Dream About Drowning And Autopsy

this dream was a year ago. for context, at the time i got easily annoyed with the friend in my dream, and i always felt guilty about it. it started off with me and my mom on a boat (it was a medium boat with a small downstairs area) we were talking about throwing a party on the boat and talking about what to eat, when then it suddenly cut to my friends point of view. (me and my mom were no longer on the boat) she was in the downstairs area with the door closed. the boat started sinking and i could feel her drowning (my biggest fear is drowning so i was freaking out) but i could feel every single detail, such as not being able to breathe, etc. after she drowned, it cut to me and my two guy friends in a parking garage. one of them showed me his phone and said “hey did you see this instagram story?” and i look at it and its my friends dead body on one of the autopsy tables. it was really graphic and i could see her skin was pale and blue from drowning and i could see her skin melting? or falling off idk. i started having a breakdown in the dream, and that was the end. i sobbed a lot when i woke up.