ALL - from diagnosis to gone in the week from hell!

My beautiful, fit, sporty 23 yo son thought he had a cold and after a week, went to his GP. 'It might be a virus, come back in a week if no improvement'. A week later he was admitted to hospital and diagnosed with leukaemia, 5 days later he was moved to ICU and 2 days after that he died. In ICU, his nurse went for a break and he began hallucinating, thinking we were pulling an April Fools prank and began to pull out the leads connecting him to the monitors. We tried to hold him down and called for help but the nurse in the bay next to us was barrier nursing her patient and she couldn't come. This was so frightening. I haven't found any other stories of people with leukaemia dying so quickly - there seems to be treatments to try and months to say goodbye. Years later, a haematology oncologist told me that he probably didn't die from the leukaemia?? Then what was it - we can only know what the hospital tells us??