As per what I have read and tried it on myself, we need to literally feel the feelings by having a strategy in place:
When we feel jealous, I perfectly agree with you in that, it is only a feeling but not transformed into improper behavior.

The following strategy works well for me and I suggest testing it:

Feelings arises from mamilian brain leading to fight or flight mode. First check where that feeling shows up as a bodily sensation. It could be a feeling heaviness in the chest or rumbling stomach. The key is to become aware where and how it shows up in your body. This was you have shifted your attention from the mamilian to reptilian (physical) brain. Now verbalize it by coming out of you. What I mean is instead of saying I, say your name as under:
" Your name____, it is OK to feel jealous and that is a part of you. Your name ___, now that you are aware you are jealous and your sensation of rumbling stomach is no longer serving you, please breathe into the sensation and let it go.

When you do this talking you are using the prefrontal thinking Brain.

Now you take three deep breaths into your stomach. Now think of the same event that caused you to feel jealous. On a scale of 0 to 10, 0 being completely neutral and not jealous and 10 being very jealous, what is your number now?

Let's say it is 3. Then keep verbalizing with conversation as above or use Emotional freedom technique and deep breathing to bring to 0.

Initially it may feel weird but once we create a habit, handling not so good emotions will become easier. The above technique made sense to me because we are consciously integrating the three parts of the triune brain reptilian, mamilian and neo cortex and that is exactly what is needed to self-regulate.