Lakerat,
For us, separate studies does the trick. Everybody needs someplace to hide, at least I do. They want to come in here, they are in Dad's territory.
If things get really crazy, Bose makes some great noise cancellation headphones.
Seriously, I think it is great to spend time with spouse -- meals, lunches out, hanging out in the morning catching up on stuff together, but we are both 'doers' and are happiest when immersed in our projects. She loves having me around, but that doesn't involve literally being together doing something all the time-- it is more just knowing I am around. I'd say be sure to give yourselves space.
On the financial panic front, these things definitely happen. Re-read the SWR literature -- are you within a reasonable safe withdrawal rate? Can you convince yourself that all the SWR craziness will work over the long run? My favorite remedy is to work on your 'Plan B' -- scope out a downsizing option, another country or a smaller home near where you live.
The other thing I do is to have some part time work that I really enjoy and which doesn't feel like work. Am about to get my first sculpture commission for a bust of a neighbor's 5-year-old kid, and my yoga teacher told me this week I am ready to start teacher training, which I may do this fall. So "work" doesn't have to involve stale air, flourescent lights and suits. Anyway, it can be a nice way to make financial ends meet, since 5k a year of income, easy enough to make, is sorta like an extra 125k in the portfolio from an SWR perspective. When SS kicks in, you can let that take over.
hang in there -- I think we've all been where you are and it hurts, but it doesn't go on forever.