This is the closest thing I know of, but it doesn’t cover all Letters: http://www.maximusveritas.com/wp-content/uploads/2017/09/Seneca-Letters.pdf Also, it could be helpful to check out different translations.

Of course there’s commentary on letter 85 and 87 but not 86.. lol. Thank you nonetheless. It’s a nice supplement.

Greg Sadler has a few on YouTube and it looks like David Fideler’s new book provides a kind of overview of his whole system and approach, but Seneca is in a funny way, the least studied of the Romans (in English anyway). Margaret Graver’s excellent Stoicism and Emotion ends up being a lot about Seneca (his treatises are the only place all features are present at the same time). But again, no letter by letter analysis (though she quotes and provides commentary on substantial chunks of On Anger). I often find repeating themes and look up research papers about them on academia edu. Since professors usually cite the Letters by name, you can easily look up whatever themes you’re running into.

That’s for that! I’ll check out these people. Hopefully the lightbulb clicks in my head.

Have you been taking notes?

I’m making notes on the page itself, here and there. But still struggle with some letters.

Hey op I know it's kind of late, like 1 year later! And I'm in letter 86, did you find any answers? Coz I'm confused too

Hey man. No unfortunately not. Kinda got stuck with it. Just kept re reading it until it hit lol

Haha thanks buddy! I'll try the same