Thinking about doing something stupid and stopping yourself is a normal behavior. Not being able to stop yourself is an abnormal behavior, and you better seek some real counseling here. Hopefully, those of you who have known people in these situations, or if you've been in one yourself have come away unscathed. But that's not always the case. Once you lose your temper and react violently, you have lost control.
People can lose their lives that way.
There's no dignity in dying for love. My friend didn't hurt anyone physically, and for that I'm grateful. That doesn't ease my heart or mind though, because I was so shocked that this person could even react violently. Anger, jealousy, rage all negative emotions. All too menacing.