My Brother drowned in front of me

This happened almost 11 years ago...and I have been healing, but the event still huants me. Billy was truning 30 celebrating his birthday. It was him, me and my other Troy....none else was there. We were all drinking. Billy started running and jumping into a kids pool as Troy and I were talking. He did this a few times...the last time I saw him floating and I pionted it out to Troy..but we both agreed he was joking..so we kept talking.
A few mintites later we checked on him.....he didnt move, so we puled him out. Troy pulled one arm and I the other. We got him out of the pool laid him on his back. His eyes had a blank stare, like he was gone. But he still had a heart beat, we called 911, and I gave him mouth to mouth until they came. We both thought he would be ok in the morning, we were unable to think anything else.
Three days later they told us he was brain dead.
Billy was the one born after me in the family...I was two years older than him. I never thought I would have to live without him by my side. He was the closest person in the world to me when he passed away. I could share anything with him, he listened and didnt judge me.
I had the same nightmare over and over when asleep or TRYIng to go to sleep. I would see him when he was running to jump in for the last time and instead of doing nothing, like in reality, I would runn in front of him and scream NO!
I would scream in agony to God to take me too.
But I am now learning there is nothing I could have done to save him, it was not in my hands..I did not know, so I could not have changed anything.
BUT It still hurts and when I hear an ambulance I often still brake down.
I love my brother, I love my brother Troy to...he hasnt gotten any real help for this, and he drinks a lot...I pray for him everyday.