I've had 2 males die on me in the last week.....Why? I just don't know what went wrong. The only thing I did was take them out of a very small tank and gave them a very large one. I primed the water before hand made sure there was no ammonia present temp was fine ph etc. Within a week they displayed all the symtoms that you have described with your fish. Was it the change that they didn't like and stressed out? Was it the water? Were they sick in the first place and giving them a change exacerbated their illness. I will never know. I hope your fish pulls through keep positive your doing your best... thats the main thing.Rught now he is literally laid on his side on the bottom of the tank. I've never seen anything like it!
Maybe if I add some endlers it will liven him up?
Tbh I don't think he will he's just laid there all the time. He's got no interest in anything.