Dr Ralph, I realised I had the same issue early this year, but not to the same extent!
And it was confirmed when I moved from a house with two cellars to a small unit with a storage cage in the car park last week! It took me two car trips in our large family car with all the seats down to lug the wine over. That collection takes up most of the 2 cubic metres we got! I suspect that is not a patch on your haul.
But realising I was buying way more than I drink (I only get through 1.5 bottles a week), I have very consciously and deliberately done the following since I came to that realisation:
1. organised wine events and get togethers where I could share some of the amazing purchases with people I know really appreciate fine wine (I know several people on this thread will attest to the good wines that have been shared in this way)
2. Stopped buying a bargain for a bargain's sake. I did that a lot in 2015. It's really hard. But I have managed to resist.
3. Instead, I am only buying the absolute best my money can buy, with minimal risk. It means I am going to miss some absolute gems on the risk issue. It means I have stopped buying from VinoMofo. But I don't care, I still get to drink 2 glasses of wine a night 5/6 times a week with my evening meal, and know its going to be a great wine. I (mostly) won't touch a wine now unless it has at least a 95 rating from at least two different wine critics I trust.
4. I share cases almost always now. I have developed a little racket in Sydney with a few close AFFers. I rarely take more than 2 or 3 of anything. It stops me accumulating more than I know I can drink, share or gift.
5. I gift a lot of wines. There's no point hoarding and letting a good wine go to waste when there is always family, friends and work colleagues (and for you and I, clients) who will appreciate a good bottle of wine. I love gifting and being generous.
6. I break the number one rule of Dr Ralph! I will drink the wine I buy early, in the middle as its developing and then one or two in the sweet spot. I love to see how a wine develops over time. It's part of the appeal of wine to me. And it helps me learn what I am drinking. And it keeps my numbers in storage down.
7. EDIT: I ought to add another thing that has kept me away from the chase of a wine deal too many - writing and learning about the wines I buy. You and I write for a living, so it's in our DNA that art of forming a view and articulating it eloquently. It's a great distraction from the buy buy buy threads, and is great fun.
I have been really strict with 2. and 3 this year. I am probably buying only one or two six packs a month, on average. I say average, as some months I don't buy anything and then others, I buy a fair amount as there are great deals on great wines that tend to come in waves (EOFY etc).
It will take me some time to get through the excess purchases, and it means I am drinking one bottle a week that I don't necessarily want to drink now (the bottle I have open for night 3 tonight is a case in point - the V&A Shiraz 2012 is a little young, but I have 6 to get through and many, many more 2012 bottles from different producers). But that's the consequence of buying too much young wine that I am never going to get through.
In terms of 6, I know you have said you have so much wine that you just don't need to do that. But I suspect you need a serious sell down to get back to what you'll actually consume within the lifespans of the wines you've got. For instance, if you have 100 98 vintage wines. I'm sure most of those by now will be on the decline unless they are the serious, serious long termers. So you may as well shift most of those that have peaked, even if you will be selling them at 50%. 50% of 90 bottles is better than 0% of 90 bottles, given your low consumption levels.
It sounds like you might also have an issue parting with your wine, if I have read you correctly. If that is the case, then I would suggest selling at least a third of your fine collection through Langtons or Greys (probably Langtons, as I suspect you have a lot of aged, decent stuff). It will be a good kick start, as you need a big jolt to change ingrained habits of simply buying, buying, buying. If you switched your online habits from scouring for the next best deal to selling at the next best price, then I suspect your buying would drop as your attentions were re-focused. I wouldn't do a mass auction of a portion of your collection as that will result in an artificial lowering of the prices (it did last year as Langtons go their hands on a large, good private collection). But a gradual sale down from your oldest first would be a good way to keep you away from the Dan's threads and the like.
As a young collector, starting out. I would really welcome the opportunity to buy from your collection, especially the older stuff and the hard to come by. I can't imagine I would be the only one. I doubt you would be losing any money given you seem to be the bargain hunter of the century and have collected much more than you have consumed! I know you are not allowed to profit from your purchases on AFF, but if you were putting up a list of excess stuff on the share a wine thread, and selling it at the Dr Ralph face value, then you would get many, many takers. If that's all too hard and public (or against the rules as its not a swap), then the Langtons option would be a good one.
I hope some of the above may help you. It certainly has helped me.
Wozza
