I am very sorry OP for your father, I genuinely hopes he has as best a time as he can with his condition.
Well to be truthful, I came here to the forum to see if anyone had any advice for myself. I am facing impending doom. This is with regards to myself, I don't wish to hijack your thread but will try my best to say how I have been coping, which is the best advice I can offer.
I am awaiting a diagnosis, it is one of the big neuorlogical disorders at best or possibly multiple myeloma which is a cancer of the blood at worst. Only the close family know. I have suffered with ill-health my whole life, some really major and life-threatening stuff, been rescucitated three times in my lifetime. What I can tell you is sometimes it is not as bad as you fear, yes I know that sounds mad reading my last sentence, but seriously it could have been really bad, the last time six years ago baffles even my doctors that this is just me now showing some reverb from that.
I always tell people who ask about the older stuff the saying "knowlege is power" is very important. I don't mean googling and worrying about allsorts, but rather finding out as much as you can about what you can expect from the disease, limitations, ways to help yourself, everything is important. It can change your life. It will help you if things go bad sometimes, you won't feel so frightened, you will act calmly and rationally at times because you have an idea what might be wrong and can do your best in that situation to the best of your own capabilities.
I have had my days recently, to my mum or husband and they both have the exact same mantra "Stay Positive". Of course I have wanted to rage and be all crazy and upset, particularly at this time of year with young kids, but you come to see it is you they are looking out for most, not just protecting themselves. It stresses you out less, that they are cool-headed, they keep you level and I think that is the best you can do for your dad. I know it will be very, very tough, but just think on it as right! My time now, this man did a fantastic job preparing me for the world and he is going to benefit from that experience now he really needs me most!
Try to keep a wrap on any emotions the best you can for him, if you need a hug or a cry, go to someone you trust and let it out or come on mumsnet or wherever to vent. Also worth looking into any forums that deal with your dad's condition, I cannot stress enough how much they can help, I have spoken and gotten terrific advice from folks on those. People that want to help. Best of luck. Not been on mumsnet a while but if I am here happy to listen if you want to vent too, sorry for the long message xxxx