My friend, this is not totally unexpected but, it doesn't make it any easier.
You have been a truly honest, loyal, and generous friend. I couldn't possibly explain in words what that means to me. All that I can do is to employ some of that very sage counsel with which you provided me. You WERE correct, then, and you ARE correct, now.
What you're describing, though, is not something solitary. Each of us travels a path trying to find happiness. Sometimes finding that happiness is very easy and sometimes one needs to travel quite a distance on that path to find it. Nonetheless, when you find happiness, the trip is deemed worthwhile regardless of the length of time spent on the path.
I am genuinely sorry that your quest will take you out of our field of vision but, I wish you well on your journey.
Ground Control to Major Tom - "We'll leave a light on for you."
Take care and keep in touch when you're able,
BST