I’m having some very weird issues with my Iphone.

I’ve had my Iphone 7 for a bit over a year and I’ve recently encountered some very weird issues. I am unable to take videos, load any sounds or any of the things I’ve made on GarageBand (to clarify, they will appear to load but will not actually play, when songs appear to play on GarageBand I get massive CPU drops and the progress bar moves at about a frame per second), I can’t here anyone who I call on my phone, even when I have full bars and any time I change anything in my settings my phone will have a CPU drop and return me to home screen (this isn’t very much so a problem just something I believe to be a related issue). This all started about a week ago, I thought it was just a momentary issue but then the problem never seemed to go away. I looked at my storage, and everything was fine. I even deleted a lot of the unnecessary videos and apps on my phone. I believe it might have something to when I plugged my phone into my PC to try to upload a file from IMovie, it went fine but ever since around that time my phone has had some very weird issues. Occasionally after turning my phone all the way off, my phone will momentarily work, but then these issues will return later. Any idea what’s happening, or how I might even be able to fix this? Even any guesses as to what went wrong would be greatly appreciated.