"She is going to kill me."
"She is going to be the death of me."
Two sentences, both relating to my (hopefully) unfortunate demise, yet with completely different meanings.
The first typically indicates that someone is upset with me, strongly enough so as to pour me a pair of cement overshoes.
The second typically indicates that someone is vexatious, and a problem, and causes enough angst as to be detrimental to my health.
It's good to keep the standard usages in mind, and not use the former when you mean the latter.