Clinical and Brain Death

For the longest time, I pondered about Brain Death and Clinical Death. I am not sure myself which I would accept as death. The brain is just as important as the heart and when only one fails. Who is to determine which is more important and when do you say your final goodbye ?
When the brain cease to recognize you ? or when the heart no longer beats ?

It has not settled or sink into me yet. I can still hear the regular beats and sounds of the life support machine and I still read the blood pressure / heartbeat on the monitor screen. The numbers tell me that he is still alive. I know legally he is not but emotionally, he has not gone.

It hurts trememdously to know that I lost my cousin and it hurts even more to remember the memories but life moves on. I know at least he saved the lives of 5 other by donating his organs.