Hope you and the bike are okay. That really sucks.

I have experienced lots of wobbles, mainly when I'm cold, shivering, and losing partial control of my stiffening muscles. Brute-forcing myself to relax my arms and shoulders is what has helped me stay rubber side down and, yes, it's a big psychological thing. Just remember you're part of the mechanical system that's oscillating and anything you can do to stop putting energy into it will help. To wit, try to relax in addition to the other helpful actions you cite.