no one will brew any more drinks so nothing is happening and they're all about to die of dehydration (even though my main stockpile is filled to the brim with food and drink...) I have no choice but to abandon nothing is going on or getting done...
How many sane dwarves do you have? Those who are melancholy or running around babbling won't eat or drink, but the ones who are still sane should be heading off to the stockpiles. They are accessible, right?
If you had fewer dwarves I'd suggest going through the unit list and marking either the sane or insane, but with a three-figure population...
I've only dealt with one major tantrum spiral (it was in my first turn in a
succession fortress and it took me nine days to start the spiral), and I think the whole thing took 5 months and 50% of the fortress.
1. Set up a mist generator where everyone will pass through it. Enable Mechanics on everyone -- that way if somebody goes insane while working on the generator, there'll be someone else to step in.
2. Build some nice statues and traps and other admirable things where everyone will see them.
3. Stop all hauling except for perishable food.
4. Stop all jobs except for mood enhancers and food and drink production. The last two may not be necessary, but try and make all your edible food prepared meals. Those are always more valuable than raw meat or plants.
5. Get a prison set up with as many chains and ropes as you can find, and place them in the middle of their own 3x3 area. That way, any dwarves who go berserk while in confinement won't be able to get to their neigbours so easily.
6. Get a hospital set up and enable healthcare on everyone, so that dwarves who get dinged during someone else's tantrum can be back to work quickly.