MAKE NO MISTAKE: having the perseverance to re-read / re-eddit, is one of the all important bedrocks of creativity. Yes. you could rattle off your screenplay, and delegate the re-reading job to a script consultant, but do that and your hard pressed consultant will be bamboozled, trying to wade through that jungle of storylines that don't go anywhere, and characters who all speak with the same voice, and a bamboozled script consultant is not what you're after.
Try and spot all the things a script editor will spot before you spend your hard earned cash. Be hard on yourself on that re-read, and strangely enough if you are hard on yourself, I can promise it will be less boring.
ONE IMPORTANT THING TO REMEMBER: you are not alone. It's really important to realise, that if you don't get to the stage where you feel you cannot physically bear to read that project again, or look at that film in the timeline, your project is not finished.