Daxton's situation must have been different because once he was on the lasix and other thing (enacard, I think), he was back to normal puppy-attitude self. He was always a very laid back poodle so he didn't run and get crazy much but he was very playful, ate well, everything else. I don't know what your baby has that's different but in our case, he lived at least another 5 years to the ripe age of 15 after beginning those meds. I hope the prognosis on yours gets better. I'll be thinking of you.
Wanted to add also that I remember being very anxious and doubtful that these meds would "cure" his problem and pestered the vet about it a lot. I guess you just have to have faith in your vet that he/she is doing everything they can and enjoy the time you have left with your baby. He may surprise you and live much longer than you think but worrying about it "unnecessarily" does limit the amount of quality time you may have left with him. And by that, I don't mean to minimalize your pain but you really need to make yourself relax and think good thoughts.