Nothing in life is constant. Everything changes. Advice?

This is a really difficult period in my life. I'm swarmed by unpredictability, everything is changing, and nothing seems constant. As I grow older, I begin to feel this is just the very nature of life; there is no escaping it. What are some resources/methods of coping in coming to terms with this? I enjoy the security of familiarity and constancy, but these things seem impossible as more and more of the responsibilities of adulthood become more and more my own. Thanks so much for any istance.