There is a good discussion on how to improve by GM Avetik (founder of chessmood.com) in episode 410 of the Perpetual Chess podcast. At the end of the transcript of the podcast you will find pointers to several of his articles on chess improvement,, grouped into categories. I especially recommend the article "Start with Why" under the Mindset category.
You can also go directly to the articles at
//chessmood.com/blog/how-to-get-better-at-chess
Elo is just a number—it doesn’t define your intelligence or character. Even the greatest players lose games regularly.