Why the hell do I feel like crying all the time?

Today a dog with a mouth cover that usually terrifies me approaches me as if he could sense my mood. And he’s smelling my feet and trying to get close to me, I’m confused as to how animals can detect that and I feel like crying and my eyes are all filled with tears. I feel so goddamn thankful a stranger’s supposedly dangerous dog actually gives a shit about how I feel. And no my feet does not have other food or anything of that sorts on it.