My feelings radically changed

I would really like to read your opinion and experiences.

Context:

I meet a super nice girl, pure green flags, a genuinely good person. I was enchanted and both like each other. Our connection was so deep and make all our intentions clear since the beginning. We both tell to each other how much we like and how happy makes us be together and the idea of a relationship.

My issue:

I wake up one morning feeling so fucking empty. Just from the ducking nothing my feelings change so radically overnight, I don’t like her anymore. I’m so confused! I’m so pissed with myself, how can I change this way and with a excellent person. How I’m I supposed to explain this to her?? (Rhetorical question don’t need to be answered)
“Srry I wake up not liking you anymore” that’s BS! Doesn’t make sense!!

I’m frustrated and it’s getting to my nerves I don’t know why…it just happened, I don’t want to hurt her 😭.

If you experience something similar please share it with me! I would really like to read your opinion and how you deal with it.