Regret and Enneagram Type 5s

I think I'm feeling regret although that feels like a foreign feeling to me.  I've always been the one to think through decisions so I can honestly later say I made the best decision with the information I had at the time.  And then I make the best of whatever outcome those decisions produce.  Regret has always felt unproductive.

So in trying to make sense of my current feelings, I opened up Google and I searched "Enneagram 5 regret".  I thought a good place to start was reading anything written about how people like me experience regret.

I almost spit out my coffee when one of the first pages I navigated to read, "How Type Fives Cope With Regret: Research the psychology of regret instead of, you know, feeling it."

When something goes wrong, my type is known to analyze it to death and then catalogue it in a mental folder one website calls "data for later" except later never comes because feelings are chaotic and burn energy to deal with.  At my core type five, I see energy as finite.

Maybe it's a sign of growth that I'm trying to name this potentially feeling as I open that "data for later" folder even if I'm still regressing to some of my core traits to analyze.  One website suggests that I 

Ask, “What do I want to do with this feeling?” instead of “What’s the most efficient explanation for this?”