I wouldn't classify my feelings as severe shame...

Unfortunately, that's not good evidence, because people with severe shame would mostly say the same thing. For one thing, there's not a generally accepted and calibrate-able shame scale. For another, admitting to shame (even to one's self) can also be shameful. ;-)

But even more to the point, one of the things that shame does is create self-induced limitations on one's behavior and thinking that prevent the shame from rising to intolerable levels under normal circumstances. As soon as you get near the boundaries of the shame, you mysteriously lose interest and turn away, before you feel anything particularly strongly.

So, instead of looking for shame as a symptom, what you'd want to look at would be what you don't think you can do, or don't perceive as desirable, despite it being generally considered desirable... and then see whether those things give rise to feelings of shame.

Think of it as an experiment in Bayesian updating to detect whether your mind has been invisibly tampered with, by observing what other people appear to be positively motivated by, that does not motivate you. ;-)