Instead, once you have your head straight, get back to "working" a full day every day on something open source. That both shows that you have some initiative, and lets you show off your chops to prospective employers.

Seconded. When I got laid off in 2014, almost everything I had that was recent enough to show was proprietary, so I couldn't. The severance was weirdly structured and that encouraged a break anyway, so almost immediately I looked for things I could do and do in public. It was good for my morale, too.