Just another one of life's lessons. I think every artist (and we are that) experiences this at least once with their art. Our ego's become bruised but guess what, we still go on with our art because we know it not only makes us feel good but also that there is someone who will love it. I have had this experience and worse someone who will tell you a "Better" way to do it (and they don't even know what a needle is). I do some watercolors and a non-artist told me what was wrong with my painting PLUS how to correct it; I gotta tell ya, I was angry (told him so years later).
Cheer UP, there are tons of people who appreciate your work.