I think creative people always have high expectations of what we want for ourselves, I also think we are the ones that see more of the real beauty in other people's work.
The trick is to know when to let go of something and post it no matter what you think of it. I know for me some of my stories that I personally didn't think were as I wanted them to be ended up to be most people's favorite stories of mine.
So cut yourself a bit of slack and if you feel like the photo has a story that you want to get out what is really wrong with that? Can any of these photo's stand on their own? YES!!!!!! FREAK YES!!!!!!
BUT
It's YOUR post, your thoughts, you need to make it yours because THAT is what makes your posts special.
Like you said, somedays when you have not any words. Post the photo alone. If you have words there is nothing worse then keeping them locked up inside you.........how I feel anyway.........I hate thinking I should have, could have and what if.......
Just be the YOU!!! we all admire and everything else will fall where it should.
Just my 2 cents!