I see that quite a few women over here struggle with issues controling how they express their emotions. I know I have a tendency to implode sometimes...
Shutting the fuck up is easier said than done, but how do you do this? Some will try to distract them self or push their feelings away. These aren't tactics that work for me, I sometimes even feel more jealous, angry or sad.
What I do is I visualise my negative emotions as a child, an extremely upset child. Then I will visualise an adult going up to the child and giving her a big hug, telling her: "It's totally fine and understandable that you feel this way. Don't be too hard on yourself!" etc. Being there with her, calming her down, not making her feel even smaller. This is so self loving that I feel instantly better sometimes and I can address the problem in a calm way instead of being reactionary.
You don't blame yourself for being upset, you accept that you are a human with feelings but your feelings do not rule you, they do not make you do stupid shit. The 'adult you' rules what you do, not the emotional child.