One of my favorite writing rules comes from Dwight V. Swain from his wise and practical book TECHNIQUES OF THE SELLING WRITER (University of Oklahoma Press):
” 1) Separate creative impulse from critical judgement.
The first a most essential step is to recognize the human tendency to mix the two.
Then, walk wise around it.
To that end, adopt a working rule of “Create now….correct later.” Promise yourself the privilege of being as critical as you like, as soon as the first draft of a scene or story is completed.
Until the draft is done, however, stick with impulse. Let yourself go in a heat of passion. Forget the rules. For as Balzac said, “If the artist does not fling himself, without reflecting, into his work, as Curtius flung himself into the yawning gulf, as the solder flings himself into the enemy’s trenches, and if, once in this crater, he does not work like a miner on whom the walls of his gallery have fallen in; if he contemplates difficulties instead of overcoming them one by one…he is simply looking on at the suicide of his own talent.””
That said, fling yourself to the page!