Sometimes the valleys in life are like potholes and sometimes they just keep growing until they look more like the Grand freekin Canyon. Hang in there bud, it will get better ... sometimes it doesn't seem like it will but it will. I'm sorry to hear about your friend, stay close to his family they will need your support.
Give yourself some time, then throw your shoulders back, lift your head up, get mad dog mean
then start climbing out of that hole and don't stop for nothin till its behind you.