Some pointers to Improve your English
To ace a language, you should understand its grammar first. Learning the grammar properly will help you in forming sentences.
If learning new words altogether is a burden, try learning a new word everyday and increase your capacity accordingly.
Try solving comprehension, write paragraphs and essays on topics. It will improve your writing habit and efficiency in the language.
Take feedback from your teachers on your writing style and grammar and ask them for suggestions to improve.
Read anything you can, may it be books, stories, comics or newspapers. Make it a regular habit so you understand how to frame sentences or improve your grammar by reading.
Watch movies in any language with english subtitles. For example, watch a hindi movie with english subtitles. That way, you can correspond to the english words which equals the meaning of the hindi words.
Last pointer would be practice. Practice reading, writing and speaking the language, because practice will make you better.