Relief

A positive emotion stemming from an emotional transition when an uncertain situation turns out for the best or when a negative outcome is avoided. Contrast with serenity.

Reference:
Franklin, J. C.; Lee, K. M.; Hanna, E. K.; Prinstein, M. J. (2013). Feeling worse to feel better: Pain-offset relief simultaneously stimulates positive affect and reduces negative affect. Psychological Science, 24(4), 521–529. https://doi:10.1177/0956797612458805