iPhone 13 refuses to turn on, although it has battery. Might be loop-booting. Force restart does not work.

My iPhone 13 has been acting crazy! The iPhone does not turn on when connected to power VIA lightning connector. When unplugged or connected VIA lightning connector, the phone doesn't turn on when I hold the power button. When I charge the phone using MagSafe, the Apple logo shows up, but not even 2 seconds after, the Apple logo disappears. When I leave the phone on MagSafe charger for a while, it's still doing the same thing: loop-booting. I tried doing a force restart/hard reset by pressing the volume up then down button, then holding the power button. I tried it while its plugged in, on MagSafe or not plugged in. It does not do anything. I know that the power button works however. A few hours ago, the phone somehow turned on. I removed it from my portable charger (I was away from home) and a minute later, it turned shut down. I had to put it back on the portable charger to turn it on. Plugging it into a Apple Computer doesn't work. The phone cant even be put on recovery mode I think. I need help with this as this is my only phone which I use for everything like contacting family, etc. I might not be able to get the phone repaired, I already spent a lot of money on repairs.