Replaced Battery, Now My Phone is Overheating and Won't Boot

Hi,

I've had my OnePlus 3 for about 2 years now and it was overdue for a battery replacement, so I decided to replace it myself. I bought an OEM battery and carefully replaced the old battery with the new one. After doing this, I attempted to charge it and noticed it was getting very hot at the top of the phone, like dangerously hot. After I got it to boot up, It would reboot after a few minutes of use and remained very hot to the touch even after removing the dash charger. So I decided that the battery must be faulty and put my old one back in and thought I'd just get a refund for the new battery. Unfortunately, the issues I was having with the new battery have continued with the old one too, so now I can't even get the phone to boot or take a charge at all now, even after trying the unbrick tool. I get the low battery notification, then afterwards I get a vibration with nothing on the screen every 2 seconds while it's connected to the charger and it still heats up like mad at the top of the device. Does anyone know what I might be able to do to resolve this problem? Should I maybe try and replace the main motherboard or the Type-C port perhaps? I explained to my friend and he suggested I might have shorted a component due to static or something but I just don't know.

Thank you for any suggestions. :)