After an update I cannot use my settings app it gives an error unfortunately settings app stoped working so reset my phone and now I cant do anything any help on allowing apps from unknown sources without settings app or enable usb debugging without setting any thing will help
There's no other way to change the "unknown sources" setting, but if you root the phone you can find apps to toggle USB debugging simply by searching on Google Play.
There's no way to replace the settings app without replacing the whole ROM. The settings app is just too closely tied to the rest of the system: it's not designed to be replaced.
It might be a wise idea to do a backup, and reinstall your ROM. It sounds like you somehow or other got the settings app switched from a system app to a user app. Without debugging enabled, it will be a slight hassle, but this is fixable.
Type in terminal emulator app:
am start -a android.intent.action.MAIN -n com.android.settings/.DevelopmentSettings
To get debugging to work. From there you run a log cat, and see what's holding the settings app from running correctly
This should work w/o root