I recently read a lament on a writing site by a young person who bemoaned her inability to write anything good, despite her great ideas. She said she was always stopping, erasing and rewriting, and that it killed her motivation. Nothing good ever got written--indeed, nothing got written at all--because what she was crafting was always worse than the other books she'd read.
If you have either of these issues--a bossy inner editor or comparison issues--then listen very closely, for I've got two things to say to you.
1. Engage in NaNoWriMo. Sign up, get in there, and write the heck out of your inner editor. Make him beg and plead for revision, and leave him supremely ignored. Make him pound his fists on the ground, and crank up your writing music. Make him leave you, slamming the door on his way out, crying helplessly that you never listen to him anymore.
He'll be back. And when he is, you can put him to work--after your rough draft is complete. With an enormous project like that to occupy him, all will be forgiven, and he'll be the one bringing you apology presents.
The original purpose of NaNoWriMo was and is to overcome the existential horror the average person feels when confronted with the task of creating an entire book all by themselves, as if they were someone important, like [enter fave author's name here]. In a nutshell, NaNo is "shut up and write". That's how the rest of those famous authors got where they are: they wrote. A lot. And you can't write hundreds of thousands of words every year if you're constantly listening to the depressing whine of an inner editor who won't let you complete a sentence without a revision or two.
Give NaNo a try. Yes, your resulting rough draft will be crap. And that leads me to my second point.
2. Rough drafts are always crap. Yours, mine, Stephen King's. I get the feeling that this is a "secret" which only some of us have learned, while others are caught up on the performance issue. Editing and polishing are basic, integral skills in our industry. Knowing what to change, and by how much, is a skill learned over time. As is the realization that what you're crafting simply isn't ready for public consumption until it's run its own gauntlet. Until you grasp the concept of the process, you really can't engage in it.
Rough drafts are the mushy dough you make after whipping all your basic ingredients together: salt, flour, oil = plot, characters, settings. Herbs and spices are your tension and crisis moments. But the recipe is by no means done. You have to knead it (rewriting and editing). It's also important to let it rest and rise sometimes, giving you a fresh perspective when you return to knead it again. At the end it must bake in the heat of an oven (here's your outside perspective, whether beta readers, an editor, a critique group. Probably not your mom. Definitely not your cat.) Only then, all pretty and smelling great, is it a finished product.
No one would take a bite of their doughy mess on the counter top and whine that it doesn't have the warm yeasty flavor of Emma-next-door's loaves. No one would sit in a pool of molten steel and complain that the car just doesn't have the acceleration to match Bob's. At least not for long.
So stoppit. These are not good writing habits. If you're going to produce a decent writing product, you need to focus--on writing it, and on improving it. The more time you spend worrying and comparing, the longer it'll take. And your audience can't read your works if you haven't finished them yet. Chop chop! We're waiting!