Do you ever get that feeling come over you while you're writing something - that sinking, nauseous feeling that what you're writing is absolute bunk? You know what I'm talking about - the feeling that makes you cringe even as you finish typing out that hackneyed sentence, the revulsion as you complete that tired and predictable scene. Sometimes, we sensitive writer types can get overcome by self-loathing as we write. It's so difficult to create fresh, sparkling work, and anything less than that seems depressing.
But you know what? You still wrote the darn thing.
It's important to get a little sense of perspective when you're in the middle of a writing project. Not everything that comes out of our pens or keyboards is going to be perfect. Most of it, in fact, will need a lot of work to get it into shape. A lot of it may even eventually get the axe. But often you needed to write that shoddily constructed scene in order to figure out for yourself what's happening between two characters. You needed to stumble through two or three bad analogies before you found just the right one. You needed to write that terrible, awful piece.
Be prepared to hold opposing ideas in your head. You may finish a day's work with that nauseated feeling of dread. You may hate what you wrote. But you wrote it. You did your duty, sat down, thought hard, worked on the words, got some of them out on the page. You pushed the bleeding edge of your story a little farther forward. And even if you end up cutting this work, you needed to write it for one reason or another. You needed to learn about your characters or your craft or even just what "liminal" and "numinous" mean. You hate it - but you wrote it. Say it with me now. Whenever you have a bad writing day, try saying it.
What to do next
Of course, we don't want every day to end with "I hate it, but I wrote it." The key is being able to take what you wrote and make it better the next day. When I'm in a hurry, I'll often write very slapdash, abbreviated versions of the scenes I hope to create. There are large places where I skip over detail or rely on jumps only I as the writer can know and skip. At the end of the day, the scene is frail and cliched, lacking my best writing. But I can use it as a kind of framework to stretch more story cloth across. It's something to work with, something to flesh out. It's a creative way of outlining that still allows free-flowing thought.
So the next time you write something you hate, take it as an opportunity to do better. Be proud of yourself for putting that very difficult effort in. You did your time; now relax, take a deep breath, and try again.