I experience something similar.

In 2nd grade, when literally nothing mattered, a teacher decided that my ADD like behaviour was a result of not being challenged enough and enrolled me in a program for advanced students or something like that. I finished the remainder of my grade school in the program, and always felt like the stupidest kid in all my classes. I didn't have to be challenged, I was just a shitty, undisciplined student. Still, despite getting B- average in highschool, the myth that I was a smart person remained.

Now, I'm in college, and probably wrongfully perusing an engineering degree, and when I do bad or struggle, family tells me I'm smarter than this and that I need to apply myself when I am, it just literally takes me longer to get things than my peers. They're cognitively ahead of me, and I don't have the capacity absorb the information like they do. Everything I learn feels exceedingly hard, where as it mostly comes natural to those around me.

So I need to sit there, knowing I'm probably not smart enough for this shit, but power through because everyone expects me to be some STEM god because in 2nd grade someone though I was smart. When I enrolled, my mom literally said "are you sure you're doing enough? I just feel like you're smarter and can shoot higher".

Like, what the fuck am I supposed to do?