iPhone shutting down and WiFi won’t work

So I have had the iPhone 7 for a while now and out of no where it kept shutting down repeatedly, then it stoped , but when it stoped it won’t let me turn on my WiFi so I can connect to the WiFi or Bluetooth, so I restart it and it let me use the WiFi for about 20 seconds then it shut down and went right back to repeatedly shutting down then after that one time it let me use WiFi it stopped shutting down out of nowhere but it still doesn’t let me use WiFi or Bluetooth and everytime I restart it, it shutdown a couple of times and stops and let’s me use it normal but without being able to turn on WiFi or Bluetooth so PLEASE PLEASE SOMEONE HELP ME, it’s the only thing I got