My dads got lung cancer

Hi im 32 and my dad is 51 he went to the doctors bk in January because he was coughing up blood and was in a lot of pain so the doctors thought he had a chest infection but he didnt believe that the pain got worse so he went to a&e and they admitted him in they done a ct scan and found out he had lung cancer which is untreatable it's by his gullet and near his heart hes had 5 days of radiotherapy and everytime I go and see him he looks so fragile and weak he doesnt eat because he finds it hard to swallow I'm in absolute pieces my mum looks after him they have been together since they were sweethearts I've got a 3 year old in June he looks a spitting image of my dad he had another scan on Friday and we get the results on the 30th may 2019 it's just so hard hes asking about death hes my dad and I cannot bear to be with out him I love him and I'm not ready to say goodbye so how do I cope with dealing with all of this when all I want to do is cry and cuddle him but dont want him to see me like this I cant take my boy up to see him because I find it hard for him to see him like this pls any advice welcome