I think you've taken the right approach and attitude with this. You should be commended for keeping the fish alive this long. It's quite an accomplishment. I don't know anyone that's kept it longer. Having said that, the fish does show signs of pinching in the dorsal musculature, which, as I've said, is a sign of starvation. It can sometimes be reversed, but it's difficult even in hardy fish. Continued luck!
Greg
Greg