Has anybody else ever experienced something like this before?

I was recently friendzoned by a girl that I have crushed on a while. She told me that she initially felt she may like me but ultimately she only likes me as a friend.
And although I’ve really felt for her for more than a few months now, I’m somehow not heartbroken.
I’m just a little sad, like I feel like something’s missing from my chest, but I also feel a little light and easy. The sadness is there but not so crushing that I’d say I’m heartbroken. Think of it as somewhere between heartbroken and mildly disappointed.
Has anyone else ever experienced such a thing? I expected to be much more crushed but really I’m okay, and I’m surprised. We aren’t even awkward around each other. The transition from potentially being more than friends and just being friends has been seamless. It’s so confusing and I’m a little concerned if I’m honest haha. What is your take on this and have you ever gone through something similar?