Indulging emotions : is doubt always an indulging emotion ? (follow up question)

So, this is my previous question and your answer about it :
“How “being on a diet” on indulging emotions is different than invalidating feelings that could be useful information ?
About indulging emotions, I don’t get how they are not useful to us like any other negative emotion would be? I mean, being angry toward something makes me realize that my boundaries were not respected, and it makes me act so they are respected in the future, or walk if it happens again and again.
How is it different with, for example, worry? To me, worry makes me point out something that requires my attention and needs to be monitored. For example, I’m worried my BF is working too much, I don’t have any control over this, but I can still point out my worry to him, and talk about it.
If I just “got on a diet” on that worry, then I feel it’s not being managed at all and could easily come back again and again until the circumstance evolves. And how is that “diet” not a way to just invalidate feelings?

I’m still new to scholars and I see there’s something I’m missing. How am I not thinking straight about all this?

Indulging in an emotion means you choose to stay stuck in that feeling. Common indulgent emotions are things like worry, confusion, and overwhelm.
When you are indulging in the emotion your action line often includes things like ruminating and inaction. Indulging looks like staying in place rather than choosing movement, growth, or change.
The best way to explore this is by working through your own specific example of an indulgent emotion in a model. The model helps you gain greater awareness of the result of your thinking and indulging in an emotion.
For example, a model of indulging in worry may look something like this:
C: My weight
T: This isn’t good for me
F: worried
A: What are you doing or not doing because you feel worried thinking this thought? Keep in mind that only actions from this feeling go in this model. Maybe this looks like ruminating or thinking about my weight, catastrophizing about weighing this amount, comparing myself to others, telling myself things like I should know better, researching weight loss options, or buffering with food.
R: I try to prove to this isn’t good for me and I don’t do things that are good for me
Worry and other indulgent emotions pretend to be useful. Your primitive brain sees this as a way to protect you from whatever you might be worrying about. However, when you are indulging in worry by thinking this thought you end up feeling discomfort in the present. Worry doesn’t drive the actions that create your desired result.

If an action in this model was to “go on a diet” we could question what that might look like. What actions does worry generate? Question how this type of diet would serve you.
What thoughts create worry for you in regards to going on a diet? Explore and investigate those thought models to learn what that creates for you.
You can always bring your models and questions here to Ask A Coach. Additionally, a powerful way to take this questioning further is to bring your questions to your weekly, private 20-minute coaching sessions. Our coaches are prepared to help you explore your thoughts and feelings, including indulgent emotions like worry.”.

If I understand this correctly, any emotion can be an indulgent one, but some emotions tend to be more indulgent than others. And for example, anger can be indulging if you choose not to act on it and ruminate, and worry is not necessarily an indulging emotion if you actually act on it and use it to drive the results you want to have? And you are also saying that worry can usually not create any actions, that’s why it is usually seen as an indulgent emotion? The whole definition of an indulging emotion revolves around the fact that you will not act on that emotion toward your desired result? Is that right?