Sorry to hear this brother. I am dealing with a situation that is very similar. The best thing for me is dealing with one day at a time, solve the issues that can be solved, and move on to the next day. Keep moving forward because you can't change yesterday, but you can try to make tomorrow better. On Feb. 6th a Radiation Oncologist told me my wife had "days, maybe a week" left..... She is over at a friends house visiting right now.
I wont hijack your thread with my story out of respect and I don't know that I'm ready to share my entire story with strangers, yet.
Peace to you and your GF.