There are so many reasons for such symptoms it would take pages to go into details. The breathing problems could be from bowel perforation and ascites(fuild in the abdomial cavity) but ascites affects animals with lungs because it puts pressure on them but fish breath though gills so I dont know about that but maybe it could put pressure on the swim bladder. Peritonites complications from perforation which would explain the blood expelling from the anal area. Although the bright color of the blood would be consistent with perforation and hemorage of the lower bowel. Altough aquarist dont often talk about this fish are biological organism and can have complications from cancer and other disorders that have no know cause or real treatment just like humans, even in their natural habit a certain % of animals will be plagued by unpreventable disease process. I would suspect you fish sufferd from some sort of lower bowel disorder, tumor, or cancer. None of these could be helped even with the perfect diet, water conditions, or any other treatment. The only symptom that throws me off is the cloudy eye which really has very little correlation to GI problems.
I probably confused you more but maybe helped at little as to an alternative cause
I probably confused you more but maybe helped at little as to an alternative cause