Hi! If I were you I would start to think about my difficulties in a different way besides calling them "stupid". So you have problems with your memory, so what? That is neither here nor there with who you "are". I have brown hair and eyes and I think my husband once said to me when we were dating that he prefers blue eyes. That's not about me, that's about what he prefers, likes, dislikes. But he is not simple himself (anymore than I am) so would not even begin to "value" me by my eye color above my personality and how I make him feel, how much he enjoys me and being with me.
Do you like being with yourself? That is self esteem. If you enjoy your mistakes, find them funny or helpful in teaching you more about yourself and your world/others around you, that's self esteem. If you groan melodramatically and grin maniacally when you make one of your really "dumb" statements/mistakes, that's self esteem. Laughing and enjoying ourselves, in all our experiences, looking forward to the next turn of the road, that is self esteem.
I went to the Caribbean in February and my genealogy researcher from London joined me there and there was another couple from England too we all met (I was with my husband). I have a degree in history and have been studying this one English line of mine (my mother's father) for the last 3-4 years, 24/7, since I hired my London researcher. I know my way around England pretty well (traveled there a couple years ago to meet the researcher then too and work with her in London) but I was talking to this other English couple about where they lived, trying to be "cool" about it all, like I had a clue, and they were saying they lived in Oxford. Without thinking, I asked what county that was in, and instantly wanted to take it back; it is, of course, in Oxfordshire :-) just like Cambridge is in Cambridgeshire, Gloucester in Gloucestershire, Lancaster in Lancashire, etc., I knew that and would have liked to have been embarrassed and feel dumb but it is funny, if you think about it and my researcher, not there for the conversation, when she joined us I immediately apologized for embarrassing her

and please don't stop letting me be your client, I won't do it again, etc., and told her what I'd said. Oh, if I think about it there is a good excuse! My ancestors were from Lewes, in East Sussex.
But that's how I helped my self esteem, I learned to enjoy myself, quirks, mistakes, and all.