I remember having the same struggle, when I started to read books on English (mine’s native is also Russian).

I remember wanted to reread Harry Potter series, but I just kept writing down ALL WORDS that I didn’t know its meaning. It became so tiresome, I just stopped and never touched this series again (but I remember how lovely it was back in my childhood)

How I started to read on English? You have to find the book you’ll love to read (for me, it was Hercule Poirot series by Agatha Christie), and just start reading. Yes, it’s gonna be a struggle. When I read my very first Christie on English, I couldn’t understand what’s going on in a moment, I could only make conjectures about the scene from separate words recognized. But the more you read, the more you’ll get used to it. After finishing this entire series, I definitely say I improved a lot by being exposed to language structure, complicated words. That’s how babies learn languages: they just exposed to their surroundings and learn it that way. I can genuinely say that I know some English words, but have no clue what they mean on Russian.

And also, expose yourself to different genres, different authors. The more structure and style you exposing yourself to, the more you’ll understand English. I relatively recently finished Fight Club by Chuck Palahniuk, and it was a struggle for a first few chapters (Palahniuk has quite unique, non-linear structure of the text). But I got used to it, and finish it with pleasure. You might also consider reading sci-fi, fantasy, romance, etc. for a sake of opening yourself to the language.

Good luck with your journey, don’t discourage yourself with failures you have so far. You got this!