strangebrew, first, welcome to psych central!

As far as alcohol/depression goes, yes, alcohol WILL increase the depression... So if you already suffer with depression, the alcohol is just intensifying it, which isn't good at all. Since you are a long-term alcoholic, the best advice I can give you is to get into a treatment facility more than just detox. It may costs you some money, but your life is worth more than money. Every state/country has rehab facilities, some long-term care, some short-term care... Do some research and find some place near you (or even a little drive away), and get yourself into treatment. Also, there should be a local mental health center that will see you. I see you mentioned you were discharged from a mental health center, but go back... Tell them you are not well and need help. They, by law, shouldn't be able to turn you down.

I wish you the best and hope you can find sobriety.