Issues with IPhone 12

i have an Iphone 12 that was working just fine when I got it, but a few months after downloading IOS15, some issues started popping up. Whenever I use the camera, it’s super laggy and when I take a picture, the whole screen turns black and disconnects my bluetooth(?) My phone also starts freezing in general after a while and I have to restart the phone and it only resets the “timer” which is for a few days before the problem happens again. I’ve been taking great care of my phone, so I’m not sure where the issues are coming form. Any solutions for this?