stop using subtitles when watching english entertainment.
watch more english tv shows and movies if you aren't already. a better understanding of culture would also help you in using more complex vocabulary.
read more, converse with other people trying to improve their English(in english obviously)
and honestly if I could give you one underrated advice, it would be to stop focusing so much on the fundamentals(not that they are not important), but sometimes in maths when you try learning harder equations and you get used to them, when you come back to the easier ones, they feel even easier. what I mean to say is, challenge yourself, don't just be bookish when it comes to learning a language
and still focus on what they teach you in school, it might not feel practical or state of the art, but it will still help you.