Have you ever let go of a hire and did that process break you emotionally?

Unfortunately, this is one of the sad truths that comes with management. Sooner or later you will have to let someone go. It's never easy. I'm not sure it's ever broken me emotionally, but it's a really crappy experience for everyone involved. 

I really don't have any words of wisdom on this one, apart from not letting a bad situation drag on. If there's someone who is affecting morale (either by performing lower than others or by being toxic), think of the good of the team. Don't let one bad apple spoil the bunch. 

But be compassionate. We are all people and for the most part all have good hearts. Just because someone wasn't a good fit for the team doesn't mean they wouldn't be great elsewhere. Everyone deserves dignity and respect.