sakshi_281,
You are in the same state that I was about 2 years ago. This happens if you have not spoken English at school.
You can do the following:
Get use to watching English news channels. Observe the way they frame sentences. Try to speak like them (I mean imitate them). Not just one of them. Try to imitate as many people as possible.
At your work place don’t use regional languages. I am from Hyderabad-AP and I know Telugu. But I told people at my work place I don’t know Telugu. They don’t talk to me in Telugu. So I don’t have to do that either.
Make new friends who can speak good English and introduce yourself in English and speak to them only in English for the first 2 days. This is important coz if you speak to a person in a particular language from the beginning of your friendship/relationship, then you will speak to that person only in that language and no other language. Even after you come to know that this person knows other regional languages that you too can speak, you will still speak to him/her only that language that you have been speaking to him/her from the beginning. You can try this. You will find me true.
It’s good if such new friends are small school going kids or teens (age group of 5 to 16) who speak English at school. If possible, take-up home tuitions for such kids. It not only helps you improve your language by interacting with them on a daily basis on their studies but also earn a few extra bucks.
I have done some of these and it helped me to a great extent. When you can write well, it will not be dificult for you to learn speaking equally well.
All the very best.