I'm with frick. I'm not being flip here, but my answer is: I'm an alcoholic.
The whys and wherefores can be useful to a limit, and help me know what needs to be changed in me (as AA teaches us to look for and accept and own) so I can better operate in the world. My mind could twist me up forever in "figuring myself out." But bottom line, it doesn't matter why. I did, I needed to stop, I did.
Now, what?
That's the great part. I get to find out. Best thing that's ever happened to me.