The strongest self-belief survives an accurate assessment of weakness.

Self-belief that requires ignoring your weaknesses is fragile, since reality keeps mentioning them. Belief that has already looked at the gaps plainly and remains is a different material entirely; nothing can be revealed that would break it. Accuracy makes confidence stronger, not weaker.

Try writing an honest account of where you fall short and read it without arguing back. Notice that you are still here and still capable of the things you are capable of. That is the version of confidence worth building.