I see this one clearly.

As you grow and mature, you realize the vastness in the possibilities of how you act, or react to events in your life. Old you would have considered a relatively limited set of possible options as a response to all of life's situations, big and small alike.

Equally, as your mind expands to new possibilities within you, you see a broader set of threats and opportunities that the world presents to you trhan you once did.

The fear you are feeling is because your understanding of your place in the world and the world itself has been growing enourmously as of late. It's a bigger, richer, more dangerous world than you once thought and your dreams are subconciously processing the new possibilities where the stakes, risks and rewards are much higher that you realized.

You haven't fully come to terms with this. You were comfortable as your old self, but you also realize that there is no going back. The richer more dangerous world was always there, and your being previously unaware of it wasn't any sort of protection. The Fangs and Treasure chests were always there, and you accept this. What you are still dealing with is your self-image or identity. Who do you choose to be that is capable of navigating this more adventurous and perilous journey. You are growing in to your new you, but the process is incomplete and you still have the opportunity to shape yourself into what you want to face the future.