Hi Lynda,  unfortunately this is normal behaviour for a lot of cancer patients.   There is a lot of anger and denial and Mum will be getting the brunt of it because she is there and we end up being very patient and helpful but it doesn't help.  Call the Mc Millan nurse he's been allocated they are meant to help you through this awful time.  When my husband was nasty to me I told him to stop it as I was the one he needed to rely on, it shocked him but it worked, or walk away, he can't be nasty if you're not there!  No matter what anyone says your Dad has to deal with this in his own way.  Try to be normal around him, men are meant to be strong and hate feeling out of control,  so that makes it worse.  He's your Dad and wants to still be a Dad despite his cancer.  I hope this helps you a little bit.   Post again if you're struggling some one will always reply because we understand .  Best wishes , Carol