I'm assuming that you mean that your CO2 tank was empty when you say your bottle. If that's the case, you'll be fine hooking up a refilled CO2 tank and recarbing. Nothing but CO2 would have gotten into the beer, so its just hanging out and aging, which is never a bad thing.
It sounds like you're right about having a leak. Once you've got a new batch of CO2, hook it up and check all the connections for a leak. If you use starsan you can spray that on the connections and check for bubbles, otherwise soapy water will work as well. Stuff like silicon tape on the connections and hose clamps can make all the difference. The other possibility are the keg connections themselves. Did you swap out the O-rings on the kegs, and did you use keg lube? Swapping out the O-rings on a newly purchased keg is always a good idea, and I know I've got a few kegs that won't seal right without a little keg lube. I've also had one that had a leaky relief valve, but the starsan/soapy water should find those for you.
