The only way of improving your English is to read, read and read in English. Try to explore and pay attention to different types of sentence structures. Don't memorize words. Memorize sentences. And use them.
This will improve your basics.
After that you can start memorizing difficult vocabulary and try to make it a part of your active English.
Try your best and include the very basic ingredient of perseverance in your quest with help of dua. God help you!