(not sure if the flair is correct, this is kinda like help/discussion? i need opinions!)

so this morning my sweet boy was diagnosed with Insulinoma, he was given around 6 months to a year with meds until we have to make the hard choice. he’s 6 years old so he’s had a good run and we know his time is coming so we are keeping him comfortable. but i’m concerned about the rest of our business, how can i keep them comfortable too when his time comes? has anyone had experience where they had time to prepare for that day to come? i don’t want them to suddenly not see him one day and get depressed. i don’t know. i just worry!!!! I have four ferrets and they are all very close so i’m nervous that when he leaves us they will become depressed.