I think you’re giving that data vastly, vastly more weight than it ought to have. Scores can only predict “in a group of a thousand people with this trait, how many of them will accomplish this thing?” I think often we’re not even competent enough yet to predict that with any confidence. I’m not sure this should have much more weight than a horoscope.
If you already know how you do in school, that’s vastly more information than you can get from your genetic data. You should basically not even consider your genetic data on any subject where the effects are also things you can directly observe. You know your grades and your ability-to-learn-stuff and your ambition-to-learn-stuff; Promethease adds, as far as I can tell, literally no information to that.
Please don’t sabotage yourself or abandon things you care about because of the output of a fairly inaccurate online test that even at its best would be screened off by ‘how do you do in class?’.