Simran First thing you need to do is get your name registered on your profile so we can use the @simran and to protect your name.
As to your issue, it is my firm opinion that this 13" machine has the same issues as the 15" & 17" machines from 2001 that ha the class action law suit. I've seen way to many of the same problems with them. Probably a reflow of the GPU is your best chance.
https://www.apple.com/support/macbookpro-videoissues/