update 16.3 issues Iphone SE

After updating my phone to 16.3 I have begin having a lot of issues including

Mobile hotspot no longer working

Spotty cell reception at best, even in town

All apps are having issues loading

Trouble sending and receiving messages

etc.

I have reset my network connections

purchased a new sim card

backed up and factory reset my phone

deleted and re-installed apps

And even still nothing has fixed these issues. I dont know what to do any more.