If you didn't hear a big -pop- when your shoulder hit the ground (collarbone), you probably have a mild separation (and it is most comfortable resting on the grip).
When you have a GS loaded on the seat and top box like yours, I'm not sure that tire pressures will make that much difference, don't lull yourself into a false sense of security. When that much weight up that high starts to oscillate in sand or gravel, you're going to have trouble saving it. I sure wouldn't want the hassle of screwing with tire pressures all the time, and I wouldn't haul around a big ol' compressor just so I could fool with them.
As many of us tried to tell the Corporate Runaways when they were hauling tires and all kinds of unnecessary crap, LESS IS MORE.