I'm sorry for the loss of your friend. I always think that these types of deaths are the hardest to understand comprehend for the family and friends left behind. The emotions of anger that they did this and sadness that they are gone are very common.
I like your attitude about feeling lucky to be turning 50 - I feel the same way and would never want to miss out on the next 30 or so years - I plan to make them the happiest years of my life.
