I have suffered with depression for five years (probably longer, but that's when I was diagnosed) and funnily enough, that's about the same time I started abusing alcohol. It was like a vicious circle - I thought the alcohol was making me happier, but actually it was making me more depressed. When I first quit, I did feel more depressed than when I was drinking, so yes I did use alcohol to self medicate in some respects, but it was actually making me a lot worse. Over time (it's been 3 months) I've learned to deal with my depression in a much better way - I no longer run to alcohol, I deal with it in a sober way, and find other things that make me happy and take my mind off it. I've found that baking is perfect for this - I spend hours making cakes, and when I've finished I look at what I've produced and I'm proud. It really helps me. Recently I decided (with my doctor) that it was time to come off anti-depressants, and I put that all down to no longer drinking. I am so much happier and healthier since given up alcohol that I don't feel as though I need medication any longer.
Maybe you do need some help with depression though? Just to get you through those first few weeks/months? Perhaps talking to a counsellor or having some cognitive behavioural therapy would help?
I promise, though, that alcohol DEFINITELY makes depression worse - it does not help in any way! And once you've been in recovery for a longer period of time you may realise that being sober is enough.
All the best and congrats on your 4 days.