iPhone 12 suddenly overheating/won't charge

I've had my iphone 12 for around a year and never had any issues until today. I used it as normal, took some videos and then it became very hot but had no message about it overheating. I turned it off as it was a worrying temperature but since then I've turned it back on only for it to be hot whenever on/charging. I left it charging next to a fan which helped with the heat issue but now it only seems to charge 1% every 5 minutes or so and the percentage drops significantly after a few minutes use. I've checked the battery settings and the maximum capacity is 94%. The phone is performing completely fine but just wont hold its charge or cool down.