Obviously the certificates are all invalid, as they expire in 500 years.
Back up all data. Sign out of iCloud in the iCloud prerference pane. Delete all the duplicate certificates.
Select the login keychain from the list on the left side of the Keychain Access window.
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.
Sign back in to iCloud and see whether there's an improvement.