The problem with perfectionism is that it is both an extreme standard and a constantly changing one. In the first place, no human being will create perfect artwork or writing. We are imperfect creatures with imperfect ability, and perfection simply cannot come from imperfection.
In the second, place, your standard for perfect will always change, and the market standard for perfect (or simply for good artwork) will always change. Say that you’ve gotten your piece of writing as nearly perfect as you can make it. Finally, it’s ready for the world! Then you take a quick look at it again. You are going to see something you want to change. And if you make that change and then look at the work again later, you’ll see something else that could be improved. (Cue an indefinitely delayed publishing date!)
Even if this specific scenario isn’t a problem, you will grow and change and mature as a writer or artist. And your standards for your work will constantly improve—meaning that your old stuff just won’t match that mark. Remember, it’s not a matter of throwing away your standards. Just of accepting that “perfect” is unrealistic because those standards will change as you grow and learn. In fact, that change is a good thing—it means you’re improving your craft and learning more about it.
So, recognize what is good about your current artwork. Also recognize what is still good about that old art or writing that you wish you’d never shown to anyone. Acknowledge that it was good for your skill level back then. Now keep improving your artwork.
Not only will your personal standards for your artwork change, the market changes. Constantly. Grab a Dickens novel off the shelf and read a page. (And if you don’t have a Dickens volume, get one. A Christmas Carol is a good place to start. :-)) Then read a page of Tolkien’s work, a page of Stephen Lawhead’s, and finally, a page of whatever YA book you happen to have on the shelf. There will be marked differences between all four volumes. Once upon a time, writers used run-on sentences, lots of narration, and multiple qualifier words. Nowadays, writers can’t get away with that—at least, not if they want to be traditionally published (generally speaking). Point being, pursuing perfection in hopes of being published is futile. By the time you finish 10 years of revising and polishing, the market standard for good writing will have changed, and chances are, your novel will be dated.
Again, it’s not a matter of throwing away high standards for work. Just of accepting that some of those high standards are unrealistic because the market changes, and because you will grow and improve in your craft. Embracing growth is better than wrestling a piece of artwork into “perfection” anyway. And guess what? The more you learn and improve–the closer your work will be to your high standards!