First, let me say the obvious things which may be all too familiar to you. Have you received medical help for this? Some antidepressants work better than others and much depends on the particular individual and the medication. Most of the literature with which I am familiar seems to say that the best way to approach this is a combination of medication and counseling. If one counselor doesn't work try another. Same thing for medications. Obviously, since alcohol is a depressant it makes depression worse and also interferes with antidepressants.
How about support groups? There must be support groups for those who are depressed. SR is also the best place I have encountered on the internet.
Depression runs in my family. I take an antidepressant and that helps. Also I worry a lot over small things or things which I have no control over. As for having supposedly "made mistakes" with raising kids, show me the "perfect parent"! If you find one you might discover that he or she has a very imperfect kid. Who can do anything about the influence of the schools, of the culture, etc.? Do you enjoy doing anything? If so then do more of that. Don't beat up on yourself. Smile and the world smiles with you. Sounds trite but it's true.
Find someone else who's depressed and try to help them out with a laugh. O.K. Start with this, "A woman rushes into a drug store and screams to the druggist, 'My baby! My baby! He's swallowed a 22 caliber rifle bullet! What shall I do?" The druggist says, "No problem! (Hands her a bottle of castor oil) and says "Give him this! BUT DON'T POINT HIM AT ANYBODY!"
W.