What you have to accept now is that, for a while, your sobriety must be your top priority. I've been sober for over five years and no way would I drink alcohol-free wine, for fear of it triggering me off again. On your day 2 I really, really don't recommend it. Are the neighbour and your DH going to drink? Either way I would honestly cancel this, it will be too easy to lapse and then wake up thinking you can't do more than one day and it's all pointless.
On Monday I think you should make an appointment with your GP. I am sure you won't want to do this, but it's now vitally important that you take some irrevocable steps towards sobriety. I assume you've also spoken to your DH and told him how ashamed you are and that you want to change your relationship to alcohol? If not, you need to do that too, today. If your DH is a drinker too (albeit maybe not a problem drinker) he may want to minimise how much you drink if he doesn't want to think about the implications of how much he does. Hopefully, however, he will be supportive and want to help you get through this.
The book that really helped me was this one. You can download it to your phone or tablet and read it today - I really would do this.
You'll need to start noticing your triggers. They can be unexpected things - one of mine was getting off the bus, which I associated with getting home and thus it being wine o'clock. A very common one is cooking the tea. Anticipating these subconscious cues is a good percentage of the battle - your brain will work against you initially, wanting you to do the same things you have always done. When I first stopped, I used to have dreams about having been drinking and not knowing where I was - these were quite helpful as drinking nightmares. But then my brain went through a whole phase of dreams where I'd literally 'just have one' and convince myself that was fine and didn't mean I wasn't sober any more. Fuck knows what the point of that was!
You'll need something to keep your hands busy, esp in the evening. I used to play on the Nintendo DS (Animal Crossing, lovely gentle game) and then I rediscovered knitting. But something to keep your hands and mind occupied during the hours when you're tired, maybe bored, at the end of the day.
Finding some good taste substitutes is important too - although as noted I wouldn't go near alcohol-free equivalents of booze. Ginger beer is good, or the San Pellegrino lemon and mint, which tastes a bit like a mojito but not too much. Herbal tea also good.
Social situations are hard. At first I was keener to meet friends in the pub as usual but I realised they were quite happy not to drink around me and so I will normally suggest coffee now. I started telling people almost as soon as I quit, before I lost my nerve and started making up reasons why I shouldn't tell people. So basically everyone I know - friends and family - knows I don't drink and why. I made a plan with close friends that if I ever had a really bad day at work and said 'that's it, I'm going to the pub' they wouldn't say 'no you can't do that' - which would make it twice as likely that I would - but would encourage me to wait for 20 mins and see if I still want to. I never had to call on my emergency plan but I'm really glad I had it.
It's tiring having to anticipate everything but you get used to it. It's impossible to regret giving up booze - it brings nothing positive to your life.
Well done on making it through day 1. I used to read posts on MN from people who had quit and thought 'that could never be me' - until it was. I was very ill by the time I stopped drinking, which helped in one sense as it was now real, there were measurable side-effects rather than just 'knowing' I was drinking too much. I think about drinking every day - I always will. But accepting that and staying sober anyway, that's the game you're in now. Good luck.