I struggle with this big time, for example, I paint and I am part of a small online artists group where we share photos of our art work and have an agreed 'constructive criticism policy' if CC is asked for. I've done three pictures that I'm not sure about and so have asked for CC but it's never been forthcoming so my conclusion is that it's because my pictures are that terrible that nobody wants to be the person to tell me. I have a web page with my artwork on it and it has a far few people who have subscribed for updates but when I post a photo of my art work it gets no comments, likewise when I share a picture of my artwork on various FB groups it gets hardly any likes or comments, maybe 3 or 4 out of a membership in the hundreds.
Now a group I know want to arrange for an artist to do some paintings for them, the other day I was approached about paintings 'because we thought you might know somebody who could do paintings for us'
They are all telling me that I'm no good aren't they?