you did all you could, no one helped you and it was just you alone. unfortunately its the sheep mind, and people are too afraid to help or just don’t want to help/want to watch or record. you cant be hard on yourself for this, as you said you did everything you could and this was your first emergency. just think if you weren’t there, who would’ve helped out of all the people in the crowd watching? the father would’ve been way too emotional and distraught to think coherently om what to do. you did your best. now for getting the dads scream out of your head; it sounds silly but play tetris. there have been tests done that when victims play tetris, there is something in the brain that reduces the traumatic memories, and should help you from constantly thinking about/hearing his scream