I have no idea where else to go, sorry to barge into this reddit with hundreds of questions.

For the last week I’ve noticed that my two year old iPhone 12 Pro Max has not been charging at night, which is a problem I’ve never had before. My battery capacity is 81%, it should still charge.

Tonight I was charging it in the car and it suddenly started tremoring, it sounded like one of those joke buzzers when you hold the button down. My screen flashed green on the side so I unplugged it fast. Now it’s at home charging but won’t seem to hold the battery percentage very long, it’s dying quickly. What the fuck is going on?