Can hardly hear volume on all apps

Miki Wall since this just happened and you did not mention anything about any other history, I'd suggest a factory reset. You do need to backup all your personal files (music, pictures etc.).

Back up data on the internal memory, Backup and restore.

From the Home screen, tap the Apps icon.

Tap Settings.

Scroll to 'Personal,' then tap Backup and reset.

If desired, tap Back up my data to move the slider to ON or OFF.

If desired, tap Restore to move the slider to ON or OFF.

Tap Factory data reset.

Tap Reset device.

If you have screen lock turned on, enter your PIN or password.(make sure you know/have it)

Tap Continue.

Tap Delete all

for more information about how to restore it etc. check this site. Regardless which provider, the procedure is the same.