I just got a heater for my 1 gallon tank so I did a water change my fish was doing good until about an hour after I put him in I did it properly slowly introducing him to the water he started hanging out towards the bottom, breathing a lot, and coming up to get air more than normal hes not moving and currently lying in his side I touch the water he swims around. Did a water test and everything is perfect. Is he in shock should I turn the lights off? Help I don’t think he’s going to make it!!