Dear if you want to improve your english then first of all collect material of english essay that you got from optional subject and compulsory subject.After that you practice when you have enough material and check yourself.Read englsih grammer from wren and martin book.There is no need of englsih teacher.But first of all collect material and then practice which make you perfect in englsih.I don't practice essay and i saw many candidates who don't practice essay and passed essay exam.Writing skill automatically improved when you make notes of different subject from books.My writing skill is automatically improved when i make notes of different subject.However for englsih grammer you read wren and martin.English essay required extensive knowledge when you have knowledge you automatically write on any topics without any problem.You make notes of democracy ,governence,education,terrorism,human right,woman empowerment,global warming for english essay.Bur first of all collect material and then practice.