Easier said than done but one needs to remember that it's about writing the first rough draft. Or for some, they call it draft zero because it's supposed to be messy. The editing is for later. Some even jest that they have to mentally tie down or duct tape to a chair their inner editor in order to keep them quiet and push forward.

You have 1667 words to write a day, focus on the target and the words of the day. Read back only a little to get back in the flow to keep moving but don't go to the start and read all over. It's messy. That is okay. Just write.