My dad has cancer

Hi! I was recommended this site, so I'll try to sum up my situation.

I live really far away from my parents, so I visit them only a couple of times per year for a longer period. I'm at their home at the moment to spend Christmas with them.

My dad was diagnosed with chronic leukaemia in 2016. He also has diabetes. The doctors said that the cancer is still not that bad and he would live for another 15 to 20 years, but he's been getting a lot worse in the last 1 or 2 years. He's been hospitalised about 3 times since his diagnosis, one of these occasions was really serious, we didn't even know for a while whether he was going to survive, but he got better. Sometimes he's feeling better, sometimes worse, and I'm always really worried when he isn't feeling well. Because of his diabetes his legs hurt quite often, but he can walk alright. He moves around quite a lot, he likes to do the shopping almost every day, but he often complains about feeling unwell and sometimes has difficulties with sleeping, and he often has problems with bleeding and injuries. Sometimes he starts talking about what will happen if he dies and all, and it makes me so terrified, even though his mom, my granny, used to do the same thing, she had the same type of cancer and she used to talk a lot about her death for several years before she actually died.

My relationship with him is pretty complicated. We like each other, it's just that he's been a really strict father with very traditional views, and he raised me to consider him as a superior person instead of a friend, so I see him as a kind of "strict boss" instead of a "cool dad" figure. So we're not really close, we're very different, we don't have much common interestes or topics to talk about, and I normally talk to my mom a lot more often than to him. But he's still my dad and he raised me up and worked hard to be able to give me food and clothes and education and everything, and I hate seeing him sick with cancer. So I feel really overwhelmed about this whole thing. I'm generally really bad at coping with stressful situations because I'm autistic. I feel like I'm a bad person because I can barely even be around him, I always panic around sick people even if it's just something like the flu or whatever, and I'm sick of blood, and the whole thing is emotionally too much as well, I just can't stand seeing him like this. My mom supports him with everything, so he isn't lonely, but I still feel really selfish because I don't spend much time with him. While I'm at my parents', we have dinner together every day as a family, but that's pretty much all I do.