I am sorry you are having a bad day, maybe have had several disappointing days in a row.
I am also sorry you did not have parents that cared enough about (did not know how either) you that they helped you slowly learn how to build your self esteem despite the challenges of not being perfect and needing time to slowly learn your strong areas because everyone has something they can be good at doing.

I don't believe you are not smart enough or are incapable of learning. Truth is we all learn a little differently and one of the biggest failures in humanity is assuming we all are supposed to learn the same way. In fact some of the individuals that have contributed amazing things to humanity have been individuals who did not learn the way it was deemed they should. Also, some very historical figures who ended up standing out that we read about also struggled with some kind of mental illness, did you know that? Even some of our presidents had challenges like ADHD, PTSD and depression and challenges with anxiety that they hid. Abraham Lincoln struggled with MI and often isolated and suffered some very down stretches. Did you know that one of the medications he took before he became president had mercury in it? He did not even realize he was actually poisoning himself. It was believed that Mercury was helpful to take for one's mental and physical health. It can actually be enlightening to read about some of the individuals that stand out in our human history because pretty much all of them had challenges. And many of these individuals struggled with some kind of dysfunction when it came to the families they grew up in too. All of these individuals grew and learned their entire lives too. None of them were "perfect", none of them.

Truth is, a lot of people simply do NOT understand, and a lot of people tend to learn how to "hide" a part of themselves, the part they "feel" is not perfect and every human being has something about them that is not perfect.