I've had a few long term jobs that I really liked and loved the people I worked with. So leaving is always bittersweet. But then you start a new job somewhere and make some new life long friends and you realize you'd never have met them and had the new experiences if you didn't leave the last and start to realize that's the way it was all supposed to work out. When it's time to move on it's time to move on, which sounds like you already had that figured out.
One of my favorite feelings in life if finding out what's around the next corner, and it just so happens that can also be one of the scariest things in life.