Joining the English speaking course will not take you anywhere if you are already not very good with above three and you just need few tweaking there and there by an expert. My suggestion is that you bring English into your daily routine. Start building interest in watching English movies, series etc it will help you learn their culture and you will also learn native way of pronouncing words. Read English literature, news-papers etc. You may widely find two kinds of literature British and American. American English is very easily available in India in form of Hollywood movies, TV series, web-series etc. If you get lucky and build your taste in watching movies and reading their literature, you will be at par within 6 months of time.
Om Prakash
Students