Well, I have a similar difficulty in analyzing myself. So you are not alone.
But I also struggle hypothesizing others' reasons for behavior. I can readily empathize with others, but often can't transfer from the emotional response to the underlying reasons/logic.
Does anyone else feel the opposite?
I can much more easily intuit how others feel and synthesize hypotheses on why they behaved the way they did than I can with myself. I have an infinite number of framings and reframings to choose from when it comes to my own behavior that it's difficult to objectively choose. I constantly ask myself how do I know that my own model isn't unconsciously avoiding negative feelings or conversely biased toward being too critical? So much so that I simply give up more than I like to admit.