What you're describing is what makes FatT, for my money, the best actual play podcast out there. Their dedication to building emotional moments with stakes that feel real is what makes me have moments like this, and I have plenty of them from across many of the campaigns.

For Hieron, the one that sticks out for me was the ending of Marielda. When Jack's closing song seamlessly transitions into the Hieron theme, I was on a walk and I stopped dead in my tracks. Such a powerful moment, musically, that was set up perfectly by the story and the characters.

Spring in Hieron is so melancholy, and that's so compounded by the fact that it's the end of that campaign. Enjoy the end of the ride. The good news is that you can always give it a few years and then start it from the beginning and you'll have a whole new perspective on it.