Peritoneal Cancer - Anyone experience symptoms toward the end - of loved ones?

my mom was diagnosed with peritoneal cancer three years ago and started a third round of chemo in September. 

She has been on Doxil. 

After starting the Doxil she began having fluid retention and more recently has started vomiting. She is unable to eat and had a nose tube for a while.  She then began vomiting due to the food being put in her belly by the nose tube.

The latest news from the doctor is the 2 years we thought we had might go down to 3 months. 

I am just curious if the vomiting is a sign of hte cancer taken over. 

I am just very confused as we thought the vomiting was from the Doxil and her anxiety, but the recent thoughts from the doctor are shocking. 

My mom was considered to be in the top tier of chemo responders - meaning she responded very well to the chemo and the cancer vanished quickly.