Apple last update completely ruined my iPhone 6

So after iOS 12.5.2 the phone completely go crazy

-Flashlight doesn’t work

-Microphone doesn’t work(although those were working fine before the update )

-Sleep button work sometimes but after i call somebody it doesn’t work anymore

Now on iOS 12.5.3 (current version)

i thought updating the phone will fixes previous problems but now my phone almost pretty un usable

-Sleep button doesn’t work at all this time

And let’s not talk about the horrible battery life and the decrease on cpu frequency from 1.8ghz

to 1.4 ghz

please help me downgrade or do anything to fix those stuff