Prius 2011 V p lock malfunction issue

About 3 months ago during Christmas eve i accidentally left my warning lights on for over 4 hours draining the 12v battery completely. I took it out and charged it over night & put it back in its place. The car drove fine for three months. Fast forward to now. I tried turning on the car this morning, but all i heard were crunching noises coming from the brake pedal after pressing it. The dashboard lights on, but it disappears after i press the brake pedal followed by a message displayed on the dashboard “p lock malfunction error msg” the p button constantly flickers on and off as well. Dome light does not turn on. The only lights that actually turn on are the lights that turn on automatically when you slide the mirror covers.

will replacing the 12v battery solve all my issues? Or is it something more serious?