Gosh I'm so sorry for you and your dad. It sounds like we are both feeling the same way at the moment it's so so hard.
How is your dad in himself? How are you coping? Talk to your family they are there for you always but if you want to talk to someone else you can message me anytime, I'm right there with you.
My dad has just had a CT and he will get the results this afternoon (because he's in hospital). He was quite sick yesterday but that seems to have settled. He doesn't have any friends or family (his own choice) so it's just me that helps him, he's coming home tomorrow all being well and thankfully he only lives round the corner as I've 2 boys both with autism. It can be really tough but I just try to remember I'm only one person and can only do so much before I snap.
Dont fight how you feel inside, if you feel sad then cry and that's OK, go with your emotions and don't fight them. Everything you feel is normal, sometimes just knowing that is a comfort.