I just wanted to add that it is perfectly possible to be an atheist but to still believe that life has a spiritual dimension, just not one that has a supernatural deity pulling the strings. That's kind of where i'm at, so i see this life in the context of a much greater journey, and so anything but futile.
Even in purely physical terms there is beauty in the connection between all living things and in the cycles of nature, and a sense of peace in knowing that everything we physically are is the same stuff the stars are made of, our water is the same water that dinosaurs drank etc, and that we are privileged to be able to understand and contemplate our place in the chain of life. If that is all there is then it is still pretty amazing.
In terms of living without a faith, i agree that it is all about kindness, compassion, doing as much good and as little harm as possible. Make the most of each moment by being fully in the moment. I recently had a health scare that made me realise just how precious and important this life is, regardless of what may or may not be beyond it. If you think it is going to be taken away from you, you cling to it all the harder.
Have you ever looked at Buddhism? I'm not suggesting you need any kind of faith to find your way, but there are secular schools of Buddhist thought that may at least show you that there is a way to find meaning and purpose beyond the mundane, and without any recourse to gods of any description. This is a good place to start if you're interested.