I am a native speaker and I teach English in the system of higher education in a foreign country, I have a master's degree, and I have been successfully editing for Cactus Global and True Editing for several months. Please email the work to me and I will edit it and email it back to you. I generally edit for $0.015/word, negotiable, and I would be happy to edit a sample for you free of charge to give you an idea of my editing skills.