Self control is assimilating those emotions in a healthy way to understand the root cause rather than letting them overflow from mental->physical in inappropriate settings.

This is a cornerstone of Cognitive Behavioral Therapy, which is, in short, "I am free to notice that when this happens, I feel this certain way, and that usually relates to these outcomes. How can my behavior influence this in my favor?"

Cognitive Behavioral Therapy is not trying to teach you to hide all emotions the way comment I reacted to suggested. You being visibly sad is fine result. There is big gap between overflow and notion that "you are allowed to show feelings" is something bad.