"That's a load off my chest." and "That's a load off my shoulder."
Which one do you say?

Question

"That's a load off my chest." and  "That's a load off my shoulder."
Which one do you say?

Answer

"That's a load off my chest" has to do with a worry or anxiety that has disappeared. "That's a load off my shoulders" is related to a burden or chore that you've been relieved of.

Answer

I would say a load off one's mind  or a weight off one's mind 
I am feeling better after I get a load off your mind.