Also, try having a conversation with yourself in English and writing down all the words you use ^^ For instance, I will imagine a conversation I might have with someone in Korean. If I can't answer the questions they ask, I will look up the words and then use them. This is helpful for me, so maybe it will help you as well! :)

Use English songs! Print out the lyrics and read them/sing them until you understand the song. Then, you will always remember those words :) Make sure you write down the words as well. Try keeping a journal in English every night with new words. Once you write it, sing it, or use it in a conversation, you will remember it much better! I like music by the band Imagine Dragons. I also enjoy music from the 70's and 80's. For instance, this is a very famous English song with lyrics: https://www.youtube.com/watch?v=o6piTG5EdhQ

How about using a spaced repetition system? It's like computer flashcards. This is one: https://apps.ankiweb.net/ Tip: Check punctuation. 'Usually, I have to read these words, again and again.'

What kinds of words are hard to remember? Maybe you can break down the words into smaller parts. When people read fluently in English, they look at the shape of words instead of every letter. Maybe that could help you. I'm not sure what to do about remembering the sounds of words, though.