Why does iTunes make me log in every time I open it since upgrading to v.12.0.1.26 and Yosemite?

Question

Since upgrading to itunes v. 12.0.1.26 and Yosemite (same day), iTunes has been making me log in every single time I open it.
Not only that, but it makes me log in several times, for iCloud, for iTunes match, for whatever else we do on iTunes. It gives me like five different reasons to log in, and I have to type my password in five times.
Can anyone tell me what is going on here and how to fix it? Thanks!

Answer 1

Back up all data before proceeding.
Launch the Keychain Access application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Keychain Access in the icon grid.
Select the login keychain from the list on the left side of the Keychain Access window. If your default keychain has a different name, select that.
If the lock icon in the top left corner of the window shows that the keychain is locked, click to unlock it. You'll be prompted for the keychain password, which is the same as your login password, unless you've changed it.
Right-click or control-click the login entry in the list. From the menu that pops up, select
          Change Settings for Keychain "login"
In the sheet that opens, uncheck both boxes, if not already unchecked.
From the menu bar, select
          Keychain Access ▹ Preferences ▹ First Aid
If the box marked
          Keep login keychain unlocked
is not checked, check it.
Select
          Keychain Access ▹ Keychain First Aid
from the menu bar and repair the keychain. Quit Keychain Access.