Only turn on unless it's plugged in

Hi,

I bought used Xperia XZ 3, well its working fine couple months after i bought magnetic type c something goes wrong. I fall asleep at my desk and my phone next to me, i woke up cause i feel something heating my cheek.

While i charge it with magnetic cable, its half open cause its touch my cheek, and now my phone cant restart or turn on unless i plugged in. Now it takes more than 2 hours to charge, i used to charge with some qc 3 (18w) its last than 2 hours.

Everytime i use the qc 3 cable its charge until I replugged in back its not charging at all and phone can't charge with any kind of cable i have i try the wireless charging but is not working.

After running out of battery, ineed to hold vol +- and power button in the same time while it's plugged in to turn it on.

Any suggestions what happened to my phone?