Work for networks such as FOX, ESPN, CBS, HDNet, NFL Network, MLB Network, NBATV, TNT, PBS, etc. Live event and corporate video as well.
Please stop working for free - the people you are working for aren't doing it for free, are they? If they are, then they are 18-21 years old, right? After 7 years, you should be good enough get SOMETHING for your trouble. Just walk away from the people who are taking advantage of you right now.
It's true to say that you shouldn't expect to be paid very much for your labor as a DP or technician when you are first starting out. Working for free to learn something can be good for you for awhile, but if you invested $20,000 in a camera package, then negotiate a daily or weekly camera package rental fee, do not just donate it and expect directors and producers (especially producers) to pay you for anything in the future - they will move on to their next production with or without you. Your labor can be free for awhile while you learn your trade, but the camera package has an actual value, and any production worth getting involved in budgeted for a camera package. If they didn't, then they are a bunch of newbies themselves and you wouldn't want to start learning a trade from people who don't understand budgets or pre-production.