I've only got a couple of minutes right now but will try to write more later.
You should never, ever quit drinking cold turkey if you are physically dependent. It can kill you or leave you with irreversible brain damage. Google 'alcohol withdrawal' and 'delirium tremens'.
Of course some people have managed to do it, but the risks are ridiculous.
I ended up the same way myself (drinking all day and physically dependent and unable to cut down) after a nervous breakdown where the doctor wouldn't give me diazepam, so have been through the system and know a lot about it.
You need Librium to quit drinking abruptly, as others have said. It greatly reduces withdrawal symptoms and the risk of fits/brain damage or even death.
I think it'll depend on your GP if he gives you a prescription for a home detox as you need huge amounts of librium, compliance is not as high as an inpatient detox (where you can't obviously be tempted to drink!) and they usually need to send a nurse to check on you once a day.
You may be referred to your local alcohol service - but get in touch with them by yourself anyway. That's what happened to me and I ended up in an NHS detox unit a few months later.
I've met people who got a librium detox just in a regular NHS hospital. I guess you wouldn't have to wait weeks or months for that (?), I also guess you just get yourself along to A&E, tell them you've quit drinking cold turkey and show them your withdrawal symptoms and they'd have to treat you.
The detox (using librium) is the easy bit, unfortunately, the hard bit is staying stopped. You can use AA for support, but I'd recommend much more than that, as AA themselves admit that their long-term abstinence success rate is just 5%.
I'd recommend joining this forum straight away and asking for advice:
www.mywayout.org
Also on there is a medicines section with medications that can help you either to stay stopped or just drink a little (moderate). The founders of AA themselves predicted a day when medicines would be available. Ironically they are now available, but the medical profession isn't using them in most cases, they still tell people just to go to AA!!!
So, please, as soon as possible:
1) look up your local alcohol service on the internet and contact them
2) see your GP and beg for help/a detox
3) join that specialist forum where you will get all the support you need
Good luck to you, and I've actually managed to write most of what I wanted to, but any questions please post them here and I'll try to get back to you