Keychain not Update Passwords

My passwords are changing faster than Keychain can keep up with them.

In some cases, I am seeing passwords in Keychain for apps back in 2013, even though they've been changed repeatedly years ago. But Keychain is NOT showing the current passwords in many case.

Is there a way to have Keychain update to the latest passwords or do I have to manually add them whenever they need to be changed?

Doesn't Keychain update itself?

What am I doing wrong?

I really don't ant to spend $$$ for a password manager if I don't have to.

But it might be worth it now since passwords have to be changed so often and are becoming so complex.

I'd hope Keychain would be able to keep up with it.

Mac OSX 10.10.5