Earlier quoted context omitted.
This happened to me as well, the only way I was able to get above that plateau was to go freelance and start my own thing. Charging a fair market value for my time. Best decision I ever made.
That's about what I've decided, but all the freelance work I've seen available has been web development---the kind of thing I'm trying to escape. Freelancing for a systems programmer has a "I can't get there from here" problem, particularly since I'm crap-tastic at networking.
Unfortunately, I think there's no way to escape the need to network. But, it's a learnable skill so you just have to put in the time and effort.