Sorry, I do not think a competent person is in your budget. 20,000 words typically goes for $150-$300, depending on the quality of the original content.
I have edited novels, self-help books, CV’s, Masters' Theses, Doctoral Dissertations, Letters of Application to universities and medical schools, worldwide. I can be of assistance.
Please read my profile, and my reviews, all unsolicited. I have a great depth of experience with this area of endeavor. I can do a small section of your work, gratis, prior to award, to allow you the opportunity to review my qualifications.
I am in the Eastern US Time Zone.
Please let me help you.