iPhone 13 connectivity issues after iOS 18.2 update

About 3 weeks ago, my iphone 13 pro started randomly turning off and re-booting. I noticed I needed an update, so I updated to iOS 18.2. Ever since then, my phone has had wifi connection problems - the wifi button is greyed out and will not let me click. I would have to turn my phone off and on to get it to work, and then it would get into a rebooting cycle where it would keep restarting on its on. Then, 2 days ago, I lost all service - I cannot make/receive phone calls, send/receive text, or use any apps that require data/wifi. Again, I tried restarting my phone, I tried toggling the Airplane mode on/off several times, I rest Network settings a few times, I have also done a full reset (not the one where it erases data though as my phone hasn't backed up in a couple of weeks due to not being able to connect to wifi). I took out the sim card and reinserted it. I even watched a YouTube video where it has you basically beat your phone on your hand; that didn't work either. I am at a complete loss of what to do next. Has anyone else experienced these issues? Thinking of getting a new sim card, but I don't think that is my issue as I cannot connect to any network, including wifi.

[Re-Titled by Moderator]