It's always instructive to take a critical look at one's own writing. I find ups and downs. Of course the ups are nice to read, the scene is humming along, one is showing not telling, and then, eeek! What was a thinking? Does that even make sense? Where was my grammar angel? How did I go to sleep at night after having written a sentence that bad?
One of the first things I learned, at the first writing conference I attended was that almost everything can be fixed? Cardboard characters? Yup? Stupid plots? Probably. Grammar, spelling, punctuation? Assuredly.
I don't know if an incredibly stupid plot can be fixed, but it probably can be. With lots of work. Knuckle down to the manuscript and rewrite, rewrite, rewrite. Hemmingway did. Everyone does, or should. My understanding is that Robert Parker does not, but maybe he is better than us.
Someone is always better. It can happen that almost everyone is better. I entered a first rate univeristy from a small town high school where competition was sparse and I was an academic standout. At the prestigious university, almost everyone was better. Prep schools, big city high schools. And they all knew how to study. I had just breezed through. My self-esteem went into the toilet and then mucked about in the sewer for two years. Writing can be the same way. You are pretty good in your writer's group or writing course and then you run into people who can write rings around you. Knuckle down. And remember what they say about persistence.
You gotta show up. Manuscript in hand, synopsis, query, pitch, looking civilized and with your best manners.
It's a bitch.