I'd like to humbly put forward some of my personal views for your consideration. Practically everyone who has completed school has also passed their English exams. Unfortunately, I dare say, not everyone is very proficient in English communication. Therefore, the solution may not lie in cramming more grammar; one has to learn to apply the knowledge.
May I suggest that you look for a good institute to learn 'Spoken English'? I doubt there is any alternative way to learn to speak any language. A word of caution before enrolling: please gather information about the institute from as many different sources as possible, including former students.
Incidentally, where are you located? If you are in Hyderabad, I could assist you. The English School at Masab Tank is the best institute in Hyderabad. The classes, with only about 8 students, are interactive and follow the 'communicative' method. They are listed on 'Just Dial'.
All the best,
Regards,
UN Ganguly
[Phone Number Removed For Privacy Reasons]