Why did my fish die?

I was cleaning him out and put him in the sink a normal and he was fine... Then I put him in his tank and he started floating like dying so I was like

I was cleaning him out and put him in the sink a normal and he was fine... Then I put him in his tank and he started floating like dying so I was like ok ill try Coolin the water down maybe it's too hot for him even though it was only just over the line o thermometer so I filled a jug up with cold water. But he died.. I feel so bad I found him a nuisance so I'm scared subconsciously I killed him : maybe I didn't try to save him but what more could I do. Also how long do they live?? I had him for like 2 -3 months. My friends died within a week when we got them. Maybe I'm a fish killer Ill never forgive myself

or:I was cleaning him out and put him in the sink a normal and he was fine... Then I put him in his tank and he started floating like dying so I was like ok ill try Coolin the water down maybe it's too hot for him even though it was only just over the line o thermometer so I filled a jug up with cold water. But he died.. I feel so bad I found him a nuisance so I'm scared subconsciously I killed him : maybe I didn't try to save him but what more could I do. Also how long do they live?? I had him for like 2 -3 months. My friends died within a week when we got them. Maybe I'm a fish killer Ill never forgive myself


or:It's not your fault! Sometimes when you clean fish aquariums, the fish can go into shock. This has happened to me before. Next time don't leave the fish in the sink for too long. Remember to change the filter every other day! If you take these steps, you should have a happy, healthy fish! Have a nice day, friend!

Tags:dying,normal,