Not long ago, one of my writing students came to me, vexed because she was making so many changes to the story she was writing. Even though my response was tailored to writing, it applies to life, too.
Here's what I told her:
Change is a good thing. Get used to the idea of change because you will be making a LOT of changes throughout the novel-writing process.
Some changes will be huge and fundamental; others will be minor tweaks, but in almost every case, you will be changing your story and your manuscript for the better.
Because the act of writing puts your thinking down in an objectively observable form. Until you write it out, the ideas are merely elusive and ethereal images in your head. Often, it's only when you read what you've written that you can identify sloppy thinking, poor logic, or other problems.
Look at it this way: Writing is clearing your head; reading what you've written is the act of assessing if what was in your head was as good as you'd originally thought. More often than not, it isn't.
Look critically at what you write. By doing so, you'll often find ways to make it even better. DON'T FEEL AS IF IT HAS TO BE "RIGHT" THE FIRST TIME. FIRST DRAFTS SUCK. SO DO FIFTH DRAFTS.
So, take heart. You're a long way from having your manuscript [or your life] be what it should or will be. You're at the stage where you're putting a slab of unformed clay on the potter's wheel. The clay blob will only turn into a work-of-art as you form it and mold it as the wheel spins.
It's a process. You're at the very beginning. There's still a lot of creative fun ahead. Are you having fun yet??