Making clothes is the most effective solution to nude tantrum spirals, but I think you were too late. This is a tough problem to solve retroactively. They're too busy killing each other to put them on now, I'll warrant.
Besides that this is the same as any other tantrum spiral scenario, your first priority is to prevent deaths and other such wonderful manners of collateral damage, and secondly to find a way to cheer up the dwarves that are already angry. I recommend letting them idle with friends, family members and other depressed dwarves in a nicely furnished meeting hall as a sort of group therapy, unless they're miserable. You want to isolate those guys from the rest of the fort since they could potentially go berserk at any moment, and we all know a berserk dwarf doesn't pull punches. With luck, they should be comforted by friends, family and the amenities your dining room has to offer and then retire to a nice bedroom at the end of the month. Once they're stabilized you can send them back to work to ensure productivity and that they get some additional happy thoughts from working.
Other things to remember:
- Mist generators kick tons of ass but it's hard to design them while a tantrum spiral is happening
- Berserk dwarves trigger traps
- Your mayor and manager are pretty important assets, they can conduct meetings and make dwarves feel better