Why you need an editor
It’s not just you! Everybody needs an editor. It’s just a function of the human mind that you will gloss over errors in your own writing. You see what you intended to write, not always what you did write. So don’t sweat the details – that’s what an editor is for.
Editors bring a fresh pair of eyes to your writing, seeing every word for the first time. Missing words or repeated words will pop right out (whereas this might be your 27th time re-reading your draft and you’re too familiar with it!).