This is also, in some ways like looking in a mirror for me. I can't really add anything more than what has already been said but will say a few things. Having suffered with addiction myself it takes a strong person to stand up and admit when he has made a mistake. Like people have probably told you, the start to recovery is admitting you have an addiction in the first place. The fact that you'd write all this should give you hope because you don't want to feel like this and talking to people about it is always a good step in the right direction.
You may feel like the drink is helping but it's just working in the same way as the drugs would, it just masks the crap feelings you have in side you. It never solves them, like people claim. I don't believe any of this can be solved with drugs, if you go to a Dr and he gives you drugs, wtf?? That's no way to deal with this at all!
In terms of your job, if you do look for somewhere new, keep the job you've got until you find somewhere else. I know loads of people that have quit their job before even finding another one, then when they can't find another job they just sit around and sulk all day and it just gets worse and worse.
I to feel like i'm at a crossroad in my life, especially about my job. I too am 27 and i'm at that point now where i need to find something new, something that will test me. Maybe that is what you need, something that will test you, something that makes you use your skills so that you finish a day with a smile and you're proud of what you've done.
We're still young dude, we're at that stage in our lives where we can choose to changes certain things in our lives. Make the most of it dude! and don't be a stranger on here, we're all here if you need to talk.