Man, nothing shuts off my productivity spigot like a good old fashioned anxiety attack. I'm not sure what people don't understand about "I don't go outside".
I don't go to supermarkets, I don't go to convenience stores, or restaurants, or concerts or anywhere else I'm going to need to interact with other talking meat. I'll go to the dump, or datacenters or whatever. Places where all the other meat are Over There and aren't trying to have conversations with me. Very occasionally I will work myself up and go to lunch at a diner or whatever, but it's a lot of effort.