At what point do you call it quits?

Has anyone ever fallen out of love with their significant other? I know this is awful to say... but sometimes I don’t know why I married this guy. He is not the same person he was when we were dating/engaged... he’s a completely different person. I know people evolve.. but this isn’t it. It’s like he hid his true personality or something.

I could write a book of things he has done/said over our almost 3 years of marriage. It’s embarrassing to even make this post... but I’m being honest when I say I’m struggling.