Terry,
I know you're a cat person, so I thought this anecdote might boost your spirits a little. We have two of these tuxedo cats, and this is the big guy named (you guessed it) Tuxedo. He is a huge cat, weighing in at about 23 lbs. in this photo, and he's now 14 yrs. old. Around half a year ago he started losing a lot of weight even though he had a ravenous appetite, was constantly drinking water, and became weak to the point where he couldn't even jump up on things. Well, the vet diagnosed him with diabetes, and after he had fine tuned the dosage of insulin Tux should recieve, the cat made an incredible recovery. Getting two shots of insulin daily, Tux gained his weight back, his coat looks better than ever, and he has the energy level that he had five years ago. There was even the added benefit that Tux seems to have lost a little bit of his vicious nature, and believe me he had enough to spare.
Hang in there, Terry, things will turn around.