198 doesn't sound like an accurate score. Last I knew, on the newest version of the Weschler test, for example, I think something like 160 is the upper limit. To assess beyond that is complex and requires additional scales and testing.

Obviously that is just an example of one test- but getting an accurate score of 198 is not something one can really do on their own.

Maybe you should pursue professional testing? [you could apply to Mensa and test with them just for the heck of it to see what you score maybe?]

Also: to comment on your concern, I have a notable IQ and I find myself continually stuck because of circumstances other than intelligence.

Achievement is a whole package, not just one score. And it is difficult if you are encountering setbacks repeatedly.