I think you're going to keep getting the same answer, clara.
No, moderation is not possible for problem drinkers. I quit for 18 years. When I started drinking again I ran up against the same behaviors and problems as I had previously observed in myself. It didn't get, "re-set." I don't even want to have one or two drinks anyway, what's the point in that? I want the warm, numbed-out, quiet brain, blissful floating feeling that only comes with multiple drinks.
Marijuana is a drug that is also addictive, so trading one for the other is not "sober." In fact, marijuana and alcohol have both been proven to actually cause anxiety and depression and that becomes most clear when trying to quit them.
I don't know where you came up with the idea that alcohol, "provides," serotonin, what it actually does is much more sinister. Here's a link to get you started,
(Excerpts from "Under The Influence")Excerpts from "Under The Influence"
You might also order the book, "Under The Influence," from which the excerpts above are taken, or a newer book, "Alcohol Explained," and get the real story from a scientific viewpoint.