I've coded by myself for my own business, for the last 10 years. The best tool I found to give me objective feedback on my code is Code Climate. You can upload

I've coded by myself for my own business, for the last 10 years. The best tool I found to give me objective feedback on my code is Code Climate. You can upload your code there and get a grade and feedback, which helped me improve immensely. I also focused on learning how to write good tests and used a web app called "codecov" to understand my gaps. It's not an easy hill to climb so don't be so tough on yourself, just make some changes and improve.