You may be able to jump start the cycle by getting used filter media from a friend's aquarium or a fish store. The filter media, provided it was just removed from the tank, should have enough beneficial bacteria to help get you really going and help support the fish you currently have in the tank. If you cant find some of that, there is a product by API called quickstart that is a supply of nitrifying bacteria which says it stops "new tank syndrome"(uncycled tank). I dont know how well it works, but its better to try than losing more of your fish. Definitely dont buy any more fish though until your tests read that your tank is cycled.