Please get this book. I understand what you are dealing with, because I went through the same thing. This book helped me immensely with finding happiness and meaning in an atheistic worldview. It is a huge change and there is a lot of uncertainty, but it is an amazing opportunity to redefine life into whatever you want it to be. The default condition of life is short and meaningless; it is up to us to make the most of it and find meaning for ourselves.
I highly recommend reading this book. It is short and a quick read. It really helped me get over the uncertainty that comes with being honest about not knowing what happens after death. He frames atheism in a great light. He talks about how he has lived his life, found happiness in living according to his own rules. He talks about finding simple traditions and rituals that help him stay connected to people he has lost. It really is worth reading.
Sorry, he writes.