iphone 6 unable to download from itunes and app store or access icloud after update to ios8.3

After updating to ios8.3 through wi-fi, phone was unable to download from itunes or app store or access icloud. Nor was I able to access itunes, app store or icloud settings. The error note was a bad ID or password. Tried downloading a free song from itunes on the computer using same ID and password and was successful.

Tried resetting network settings on phone and that did not work. Nor did resetting phone using home and sleep button.

Solution that worked for me:

1) Backed up phone to itunes using computer

2) Reset phone settings WITHOUT erasing data from the General settings menu.

3) Joined home wi-fi network

Checked that all contacts, photos, etc. still there. Checked that all other settings were what I had setup before. Tried to download an app from the app store and was successful. Everything works again. Good Luck.