This is a sad time - our cat has gone missing and even though we've done all the possible things for alerts, searches, posters, neighbours, social media, no sightings at all.
I've had older cats (in the past) put to sleep when their time came, and that was dreadful, but this feels almost worse because he is a young cat, and also because we have no way to know for certain what's taken place.
Still hoping of course that he might come home but it's starting to seem more and more unlikely.