Well, I was an Evangelical Christian until I was 16, a progressive Christian until I was 22, and an atheist until some time in the last 9 months.
Each time, I found myself at the same point asking the same question: Why do I believe what I do?
I was a Christian because I felt obligated, but not because I felt compelled. When I finally came around to that realization, I became a reluctant atheist.
I say "reluctant" because even though I didn't want to believe there was no god, I felt nothing to compel me to believe any differently for a very long time, and I got more comfortable with that.
I had to experience something that compelled me to believe otherwise, and over the span of about a year some things really piled on hard that made me question my non-belief; I had a "crisis of unfaith," which is really no different from a crisis of faith, if you look at it plainly.
I think the question to ask yourself when you think about your beliefs is why? What has called you this far? What prompts you to keep going? What has it done in your life? And when you find yourself in a place to answer all those questions fairly and honestly to yourself, you will find your path easier.