My phone won't turn on and vibrates while charging!

My phone was stuck in boot loop for a while, so I just let it sit and charge overnight. When I checked it in the morning, the screen was black and wouldn’t turned on. It appeared that it hadn’t charged at all. Right now, when I plug in my phone, the screen stays black and it just vibrates every few seconds over and over, but it doesn’t turn on or show any indication of charging (neither on the LED light nor the screen). I’ve tried resetting the phone with the volume and power buttons, but the screen doesn’t even respond to these buttons.

My battery is not removable.

Please help, and thank you.