Need help fast!!!!!

[Edmonton Eskimo]

I took some of the fish out and put them in a separate bin with water from my other tank. I have the bin aerated and there is no detectable ammonia in that bin. I checked my main tank for ammonia and my test says it is 0 but my tomato clown is still struggling for air. I have been battling this since this morning do I stand a chance or is the damage already done? All of the fish are still alive(other than the wrasse which perished last night)Should I continue with water changes or stop?