For a non-native, considering a career as an author in an English-speaking world takes a lot of hard pills to swallow. Standing face to face with your shortcomings may be hard, but it also creates a space to grow.
1. You don’t realize how much you suck until you work with native speakers on a regular basis.
2. There is a massive gap between “understandable” and “well written.”
3. You need to train your “writing muscles” regularly.
4. Your active vocabulary is much smaller than your passive one.
5. You probably use too many words.
6. Technology is there for you.
7. You need editing more than proofreading.
8. A professional editor becomes your teacher.
Summing up …