[Jesus Christ.]

There's nothing wrong with drinking to gain a bit of confidence, it's quite helpful actually, but that's usually means a pint or two, not half a bottle of vodka (assuming you're on about ~40% not the cheap 20% crap you can buy x.x)
The upside is that you have noticed that you're drinking too much, and it shouldn't be too hard to cut down though, considering that you've not actually been drinking for that long a period of time. Just try drinking less, or move onto different drinks, like beers or cider and wait for it to kick in before you drink any more, it's not completely instantaneous.