Love the stuff, but I mostly use it for finishing off chicken soup and in Romanian meatball soup (ciorba de periosoare). Similar to
this recipe, except I don't use lemon juice as the souring agent, but rather a fermented rye-and-flour thingy called
zakwas in Polish (my ancestry) and
bors in Romanian (The Romanian version is usually made with wheat bran; the Polish version is often rye or a mix of rye, wheat, and/or oats. The results are pretty similar.) I have a recipe for that stuff somewhere on this site, but you can buy it commercially at Polish and Eastern European supermarkets, where it comes in a 1/2 liter bottle and usually just labeled "żurek" or "country style sour soup." It should have about an inch or so of flour sediment at the bottom and a clear-to-slightly cloudy, liquid above. It's not pure
zakwas/bors, as it's flavored with garlic usually, but that flavor is usually included in all the sour soups I make.
Anyhow, lovage just goes perfectly with it. Lovage also dries reasonably well for a fine, non-woody herb like that. The flavor of fresh lovage does take a little getting used to, I think, and the newer, smaller leaves have a more delicate flavor than the older ones. But once you get used to it, I think it's easy to get addicted to it. That said, a soup made with tons of lovage like you made sounds like it may be even overpowering for me!
Also, lovage is quite hardy in this zone. And it likes to grow and grow and grow and produce way more lovage than you'll ever know what to do with. I finally took down an old lovage plant at my old house before the renters moved in, but that plant had been with our family for at least fifteen years, and you can do nothing to kill it. If left untrimmed, it would grow four, five feet tall every season. I never did anything to take care of that plant; it just took care of itself.
Incidentally, in German, the plant is sometimes called
Maggikraut for its similar flavor profile to the Central European versions of Maggi seasoning sauce (the formulas change by region.) From what I've been able to dig up (and I did some research on this months ago), lovage is used in at least some of those formulations, though I've only seen it listed as an ingredient on the bottle this year for the first time. I think it was hiding under the ambiguous "aroma/flavorings" listing before. First time I smelled lovage, I thought, "this smells exactly like Maggi!"
Weirdly, for all the usual comparisons to celery, it doesn't really remind me all that much of celery. It's a very, very distinct flavor and smell, which I can detect in pretty small quantities, much in the way some/many people can taste cilantro a mile away.
ETA: Now that I re-read your initial post, did you blend up the stalks in your soup, too? That does sound like it would be rather ... intense. I've never actually used the stalks in any of my cooking, but I have used them as playful and flavorful makeshift straws for Bloody Marys (not my idea--I read it somewhere.)