This is one the few zombie movies which are really good and are not just about action and all making ? boom bam here and there rather it's explore the grounded level problems and keep situations bit realistic and just not glorify the maine character.

To be honest I'm not really fan of sad endings I even avoid watching movies or drama with sad sad endings but this is one of them which I watch even knowing that the ending is not really a happy ending.
And I think sad ending make this movie even more spacial.

So if you want to watch a zombie movie with emotional rollercoaster ride then just watch it without thinking about the ending I am sure you will like it.