Whats to live for

Well things had been going not to good and then they started to turn around. I had gotten a good job, trying to deal with my addiction and felt good.
Within a matter of days and hours they have fallen apart. It feels like when I start to do good and have a goal things fall apart. 
Its really depressing and I feel lost now.  I talk with my best friend who cares and I love her so much for that. I just dont know what to do