Keychain is a huge mess

Hello,

It all started with Microsoft Word repeatedly showing me the following message: "Microsoft Word wants to use your confidential information stored in Microsoft Identity [LONG NUMBER] in your keychain". As I did not know the password, I could not allow Microsoft Word to do so and had to click on "Deny". The message kept popping up, sometimes every few seconds.

I proceeded to - presumably - changing the password to my login keychain in order to then be able to grant Word the access it was so stubbornly requesting. The login keychain ended up disappearing completely after clicking on "Preferences" -> "Reset Default Keychains" in the Keychain Access app.

Now the login keychain is back (apparently, don't ask me how that happened). However:

• I can't change the password to my login keychain ("change password" is greyed out).
• I have read somewhere that you can create a new keychain, make that default and then change the password of the login keychain. I can't even seem to do that: I created a new keychain, right clicked on it, and "make default" simply does not appear:

Ever since the original login keychain vanished, weird things keep happening to my Macbook, e.g. I don't have access to iCloud anymore, I have to repeatedly log into my Apple ID, Touch ID does not seem to work, my login picture disappeared etc. etc. etc.

Any help would be greatly appreciated!

Thanks,

Jan