Hello, I'm sorry to hear that Bobby isn't himself and I'd like to help. A dry nose can be an indication that your pup doesn't feel wel or is dehydrated.
My first concern in a dog that is drinking and urinating more is diabetes. Other possible causes are a urinary tract infection, urinary calculi (stones), kidney or liver disease or an overactive adrenal gland (Cushings disease).
Is he hungrier than usual? If so then diabetes or Cushings disease are more probable.
If his appetite is actually down then kidney or liver disease or an infection are more likely.
Ideally your fellow need to see his veterinarian for an examination, blood tests and a urinalysis with culture. The sooner he is seen the better as the sooner therapy is started the better he should respond. These problems are not anything that can be dealt with successfully with home care.
Best of luck with Bobby, please let me know if you have any further questions.