mp, this is tough i know.
i'm sorry but i have a different take on this crisis.
your friend should not have put you in this situation..and by situation i meant the fact that he went on and on about this.
if someone mentions it one time, you can be there to console him and give him advice but it is unfair to burden you this way (several times) when you're powerless to do anything about it.
you can't control the world.
everyone has free will and makes choices every day.
i've learned to accept there will be chaos in life and will not take the world on my shoulders.
take comfort in the fact that you spoke your piece to him and whether he follows it or not is truly up to him.