I'm sorry to hear you're still having a crazy time back at work BBN.
I'd second Girlie's suggestion of something in the work place - a mould or a chemical that you're extremely sensitive to. I've had a strong reaction to something that was sort of like what you describe on three occasions (once in the university computer lab - I spent years working there but it only happened once which is strange, once in a museum, and once on a bus). In all three cases I started to 'leak' quite severely. Aside from a very runny nose, my eyes became so watery I crying and wanted to scrunch up my face. I can't say I remember what my mental or other physical reactions were (fatigue or fog, although I usually get foggy when I'm sick with anything) on the other hand I also left the situation fairly quickly. In all three cases I think I was the only one affected by whatever it was too. I returned to the computer lab the next night with some trepidation but without any issue.
I'm not sure what sort of work it is you do, but, in theory do you think you could 'do' the same thing if it was in your own home environment? That is, if it involved standing a lot would you probably be fine if you spent your day off standing at home all day? If it is desk-work, could you concentrate on something for 12 hours? The reason I ask is I'm wondering if you might be able to sort out in your mind if the symptoms you have are related to the exertion of the work or the location, or possibly a third aspect like a change in your diet (hydration?) when you're working. Any theory you can build up to test would help you to narrow it down.
I hope you can figure things out.
sandy mould vs mold. colour vs color.
it auto-corrected my moUld.