My Golden Retriever died of cancer. =( Her signs were not being playful, not wanting to swim or go for walks anymore (she LOVED to swim! It was her favorite thing) and her appetite was gone. I wish you luck, because not matter how hard you fight, the cancer will win in the end. It's just a matter of time. Hopefully a long time for you.
Putting them down is the hardest thing in the world...Good luck, Journey. Poor baby. =(