If your fish died less that 24 hours after posting it was probably too late to save him. A fish on its side hardly swimming is not a symptom of anything in particular and could have been anything. Its common for all fish letting go to lay side up. These things happen and its probably not your fault and definitely not AAs community. How or where would they begin to offer advice on side up fish, it could of literally been anything.
Again i dare to make a statment for AAs members and speak for many when i say sorry we couldnt help your fishy friend this time around.