What is/are the word(s) for the overwhelming feeling of relief?

I am describing in a college app essay the feeling I felt when I finally did not experience overwhelming anxiety when presenting in front of the class. I have only felt this way when presenting topics surrounding math and science.

I need a word that encapsulates the feeling of utter relief. One example of this could be when someone finds out their loved one is not going to die. The cold, unrelenting grip of worry is released from the shoulders and lungs and that overwhelming sense of relief is felt. The lightness of the shoulders. The newfound ease of breath. What is a good word that encapsulates this?