Sad day

Last night I had to say goodbye to an old fishy friend.  I've had Shade, a convict cichlid for 8 years.  I have been noticing since the beginning of the year that his color was fading and I wondered if he was okay.  He seemed okay otherwise though.  That is until he started to act lethargic and just wasn't his normal ornery self.  He wasn't chasing the other fish around and trying to eat them.  I had to put in various hidey-holes for the little fish to go to escape him and he was like a football player and seemed to use shoulders he didn't have to push heavy things around.  He would get so angry when he couldn't get the little fish and threw actual fishy tantrums.  Lately though, they could swim right by him and he didn't react at all.  I've watched him get steadily worse until last night he seemed to be stuffering too much.  Something in his side was hurting and he was flicking his body to the side like he was trying to get it off of him but there's nothing he can get off.  There's no wound, parasite or fungus although I did treat the water just in case.  I tried everything I could to help him and it didn't work.  I finally just had to help him die and it feels horrible.  He was a menace in the tank but I will miss his eyes following me around.  Bye buddy.