If you're craving heart-fluttering moments, I can point you to a bunch of places where I always end up losing track of time. For modern, serialized romance (think slow-burn office romances, enemies-to-lovers, and weirdly wholesome slice-of-life couples), I spend hours on Wattpad and Royal Road. Wattpad is a treasure trove for teen and new adult vibes, where amateur writers post everything from fluffy one-shots to multi-book epics. Royal Road skews more toward webnovels, but you can still find plenty of romantic subplots threaded through fantasy and litRPG settings.
For fan-made love stories I can't live without, I read on 'Archive of Our Own' and FanFiction.net — both are packed with fanfiction across every ship you can imagine. AO3 has excellent tagging, so you can find exactly the dynamic or trope you want, and the community tends to be thoughtful and creative. If you want classics or public-domain romances, Project Gutenberg and ManyBooks host gems like 'Pride and Prejudice' and 'Jane Eyre' for free, plus Librivox if you prefer audiobooks.
I also use my library’s apps — Libby and Hoopla — to borrow contemporary romances for free, which is how I discovered several indie favorites. And don’t forget Amazon’s free Kindle section and Smashwords for indie authors giving away promos. Every time I think I’m done reading, these sites pull me back in — there’s always a new heart-melting scene waiting, and I love the thrill of finding a hidden gem.