Someone who barely passed English but can fix an engine and calm a crying toddler is not unintelligent.

School measures a narrow band of ability and then reports the result as though it covered everything. Diagnosing a fault by sound, holding a plan in your head while your hands work, reading a small child well enough to settle them: each of those is hard and most people are bad at them. The exam just has no column for any of it.

Notice what you can actually do before you accept a grade as a summary. Write down three things you are good at that school never tested. Then find somebody who needs one of them this week, because that is where the proof lives.