No one is able to tell you whether that blog post, that book, that video, that painting, that design, that piece of art or that product is really good. No one. Not even that voice in your head.
So don't ask other people for advice or feedback. Because it's just that person's opinion. And nothing else. It's very likely that that person might not even be your true reader, listener, viewer or customer.
But even more importantly, stop listening to those voices in your head trying to tell you what's good and what's not. Because it's just that. It's an opinion. From a voice that lives in your head.
At the end of the day, the only thing that really matters is that you put your work out there and let the market decide. Let the market, your audience and the people out there decide whether they like it or not.
Let them read it, look at it, listen to it, play around with it, share it and comment on it. But first, you've gotta put it out there. Otherwise you'll never know whether it's really good or really bad.
And then, if you never put anything out there it'll all just stay there inside your head to be forgotten...