I am so sorry you are all going through this difficult time. I can't give you much advice on treatment options as my Dad was only able to receive palliative chemo., however, I can give some advice from a caregiver's perspective.
Many have said that there is no clear path for this illness, what works for one person, may not for another. Some have miraculously beaten the odds. Keep in mind that each one of us is different and responds differently to treatments, so if your dad is not successful with a protocol that has worked for someone else, try not to get discouraged. There are options that he can try and he has not exhausted all of them. I firmly believe where there is breath, there is hope, so please hang in there.
As for being strong- this is a tough one- many told me (including the doctor) that I had to be strong for my Dad; an impossibility for someone losing her best friend. So, when I needed to, I would rage. I had a friend I'd call and many times I'd scream into the phone, so angry at the injustice of it all. When I could, I would cry my eyes out because I ached for my Dad's pain. I was afraid this emotion would have a discouraging effect on him, so my one hour tearful commute always ended one block before my parent's house where I'd Visene my eyes, use a nasal spray and would plaster foundation on my face to disguise that I'd been crying. For the most part I faked my strength in front of my Dad, but there were times of tenderness when we both cried and those are beautiful memories that I cherish.
Kristin, treasure every moment! When my Dad wasn't looking I'd be staring at him, memorizing the lines on his face, I'd pay special attention to the sound of his voice, I'd try to make him laugh, I'd try to steal more embraces because I was afraid that those moments would be coming to an end. Every moment you have with your father is precious, whether it is a moment of happiness, or a moment of regret at the situation. It is a great blessing and honour for a child to be able to give back to their parent and pain is the price we pay for love.
Try not to second guess yourselves, make sure you can get as much information as possible and use this site often as there are many wonderfully wise and caring folks on here who support for no other reason than they really care. I found this site four months after my Dad passed away and I wish I had found it sooner. Come here as often as you like and say what you need to, there will always be a virtual embrace waiting for you.
One last thing, and I'm not suggesting this because I think your father's situation is dire, but you might want to consider as part of your journalling, a book on father/ daughter conversations. It gives some really good examples of questions that turn into discussions that can be healing for many different reasons. The book is "Conversations with My Father: A Keepsake Journal for Celebrating a Lifetime of Stories (AARP)" and can be found though Amazon.
I'll end by telling you that your father, you and your family are in my thoughts and prayers. These situations are in God's hands and he won't drop us.