My Question Is This. I Have Been Being Treated For

My question is this. I have been being treated for pancreatic cancer since dx`d 4/5/2013. Had a failed attempt @ a whipple proceedure in Aug 2013 due to the tumor being wrapped up in aorta. After radiation and chemo for several months my oncologist thought I had a bowel obstruction annd ref. Me immediately to another surgeon who assured me there was no obstruction, but, asked if I were interested in trying to remove the cancer with a distal pancreotomy/spleenectomy. After the surgery I was told It looked as though I were cancer free. After awaiting path. Reports for a couple of weeks it was found there was still an area of cancer on the aorta. I was then ref. To a cyber knife specialist who on my f/u visit assured me he'd gotten all of the cancer. After about a month I started having the back and stomach pain that originally led me to finding the original cancer which @ diagnosis I was told I was a stage 3 almost 4 at the beginning. After a pet scan they found yet another area a cancer growing in the celiac plexu. I am now rec. Chemo as pallative care as I've been told there is nothing more that can be done. I will be 49 on Saturday. My question is this approx. How much time can I exspect to live in this state. I am 100# was a healthy 136# when I started this journey. I know no one can give me exact dates. My oncologist says probably less than a yr. Is this about the average? Sincerely Tess Lajoie, S E Massachusetts e-mail is YYYY@YYYY . thank you for your time :-)