3 months old MacBook Pro crashed
Since your MacBook Pro is only 3 months old, it is under warranty. Take it to an Apple Store or other Apple authorized repair center immediately and let them diagnose and fix the problem.

You might have a faulty Mac motherboard, or you might have a faulty MagSafe power adapter, or, worse, the electrical current in the house where you plug in the power adapter may have substandard "dirty" power that is preventing the power adapter from properly powering the computer.

But since it is under warranty, the authorized Apple repair people will diagnose the problem for you. If it is the fault of Apple equipment, they should repair it for you at no charge.