Is this sentence correct?
Is it correct if "not to" comes after "It is up to you"?
For example, is this sentence correct?
"It is up to you not to allow your heart to be broken into a million pieces."

Question

Answer

Hi, Yes, that is correct English.

Answer

yes

Answer

Hello, my friend!  I think this is a great way to say it.  You could also write it like this. 
It's up to you TO not allow your heart to be broken into a million pieces.
It's up to you to not LET your heart be broken into a million pieces.  
It's up to you to KEEP your heart FROM BEING broken into a million pieces.  
That is some good insight though!  Keep up the good work! 
Justin