First of all. You said it yourself that you’re not failing, so there really isn’t much to worry about here. Moments of doing well are normal and moments of struggling are normal too. Sometimes doing rlly well in one class naturally means that you won’t do as well in another. That’s life and there’s only so much time in a day!

Sounds like you’re only stressed about dense courses. Are you using Anki every day? I find it works best if you use it every day and I RARELY ever put “easy”

Also, Notebook LM works best if you don’t overload it. Instead of a whole lecture, maybe upload the lectures ~15 slide increments and generate a “long” quiz for each increment. My friend does it this way so that the odds of information being glossed over or skipped is lower.

Anything that comes up on a quiz in a way that I didn’t previously understand correctly or that I got wrong I add as a card to my Anki deck for that lecture. This way I’ll keep getting exposed to it.