I keep replaying today in my head over and over again... I have no idea how parents with terminally…

I keep replaying today in my head over and over again... I have no idea how parents with terminally ill children (cancer, etc) find the strength to do it repeatedly... They had us stay in there during anesthesia... He was struggling and crying for so long and then slowly just got quieter and quieter (with the anesthesia mask over his face)..... But, even after the anesthesia took affect, he was still crying in his sleep... I couldn't deal... I regret staying for that part but they told me to talk to him till he fell asleep... I was balling my eyes out.... Every time I close my eyes, all I see is his terrified little face looking up at me