Sorry to hear about your CO2 leak; I am going through the same thing. I wanted to pass on this thread to you to at least make you think about this. It may or may not be your problem.
It's pretty easy to take your gas in connector off a keg, and while pressurized and still connected to your gas line, completely immerse it in water (or soap solution, or whatever is handy - NOT BEER! ). My bubbles were evident pretty quickly. Don't mistake a few bubbles for a leak though. There can be some air trapped inside the connector. Look for a steady, small bubble (CO2 bubbles are smaller than air bubbles due to surface tension differences between CO2 and air).
To the exclusion of any parts that could have significant contact with my beer, I'm thinking of putting a serious coat of Lubrifilm on anywhere else that might could leak...
Hope you get it figured out soon. I know how stressful this is, and we don't need to get stressed by this hobby/passion!