Terrible ending,answer to the question Please Help!

Ok so I posted a question about my couin getting a new puppy and how there older dog was getting rejected because of it, And how they were talking about putting it down because it was going deaf, well yesterday it all ended badly.

My cousin's older dog had not been eating for a while and everyone was getting concerned, anyway the other evening he was sick a few times (horrid I know) and so they made a vert appointment,well we were at school when they took him, turns out he had a type of internal cancer,they thought the best thing for it was to...put him down... I cried for ages and am still in greiving, when people ask me whats wrong its hard not to cry at the story, im begining to get over it but if you have any suggestions what I could do to make it easier please comment below. Thank you.