Jimi, if you are not religious then remove the first word of this prayer:

God, grant me the serenity to accept the things I cannot change,
Courage to change the things I can,
And wisdom to know the difference.

The examples you quote are really heartbreaking ones, you sound like a very caring friend. Your friends must really appreciate having you as a friend, if you asked them they probably wouldn't expect you to fix things for them, your caring attitude and willingness to help is probably the most important thing to them.