MacBook Pro won’t boot in any mode. Stuck on loading bar

I have a MacBook Pro 15” mid 2014 (running Mojave) which has been stuck for a day on loading bars. It all started after the computer shut down despite being at around 60% of the charge. I have tried to boot in every possible mode unsuccessfully: - In recovery mode it gets stuck on apple logo at 1/3 of the bar. - In internet recovery mode, it gets stuck immediately after passing the waiting with the globe. It stays on the apple logo stuck at the beginning of the bar. - In safe mode (shift + power button) it gets stuck at 100% of the bar in the user entry page. after option + power button, I can select the drive but after that it gets stuck again on the bar. - In single user mode I typed /sbin/fsck -fy and got the message that the volume is okay. After typing reboot nothing changed though. - I also ran verbose mode. I can’t upload a picture for the moment but I got few messages with written: failed to get apfs volume keybag and failed to initialize volume keybag. I also ran diagnostic and got Reference Code: PPT002. About the battery that needs to be replaced soon. In all the modes except when I am trying to log in normally, after being stuck for around 20 minutes or more, the computer turns off despite being charging. I also tried resetting SMC and PRAM. I can hear the fans working, keyboard’s light and its commands are working too. I really don’t know what else to do. Hope someone can help. thanks a lot!!