jam-Sorry about your friend, he sounds like an intelligent, caring and involved man. Sorry also that you feel you life was meaningless. You loved someone probably, that meant something to them. You aren't dead yet, there are still things you can accomplish to make a difference. What about going to a hospital and holding abandoned babies, born to addict mothers. Or a nursing home to read to those who can no longer read, or just listen to their fascinating stories, that will bring meaning to them. It is probably best not to compare yourself to other people, it can only bring one of you dissatisfaction.
I hope you get over being depressed. If you were nearby, I'd invite you for coffee and we could laugh about crazy things that happened in the borg.