Uh, sounds like you blew your main seal
. Specifically, the #20 O-ring that is just under the brass head that makes the high pressure seal. You will certainly feel air escaping when you put your hand nearby.
In a *clean* environment, unscrew the hex bolts and pull off the brass head carefully. You will see the main metal-to-metal Reed valve and that #20 O-ring below. It will be frayed if has blown. Replace it (you do have a replacement, right?). Wipe everything down and apply some O2-compatible lube, and put back together.
You are done.