Hi Bamoozle,
Depression really stinks...have you seen your doctor? Medication for depression is not long-term, but I found that short-term medication gave me a mental break to sort things out...I'm not an addict (but am married to one) so I can't say if sobriety sucks more than other states of being...
I'm not out to convert or anything, but have you thought about visiting a Unitarian-Universalist church? You can be an atheist (keep your "A" card!) AND a Unitarian, which I find kind of neat. There's no shared beliefs, just shared values. They're nice values, too, like a belief in the inherent worth and dignity of every person. I'm an agnostic, and have found it to be a really welcoming place that encourages self-seeking. Feel free to PM me if you want and I can tell you more