[Vent] dachshund most likely has lymphoma. Heartbroken

Just found out my six year old dachshund most likely has lymphoma. He has swollen lymphs in multiple spots on his body, vet ran some tests with the results coming in tomorrow. They said anytime they've seen this it's been cancer.

I'm shocked. He's 6, they usually live to be 13 or more years old. I feel like he's getting totally cheated out of life. He's the most high energy, sociable dog I've ever known.

With the treatment they usually live 1-1.5 years longer. How am I supposed to enjoy this time knowing it has an expiration date?

We also own his brother, I feel so bad for him that he's going to lose his best friend, whom he knew before our family.