BIG PROBLEM WITH ICLOUD

hi!

I have a problem with my icloud on mac. It all started yesterday when i tried to type in my usual password to use my mac and it said that it was wrong but the thing is i use my mac every day and suddenly it was wrong? Then i could reset it with my apple id and everything worked out. But then there came all those keychain questions, for example that i can update my keychain or delete it or do something else and finally i ended up making a new keychain i guess but it didnt work out because it didnt do anything. Then my icloud started messing with me because it asks to sign in but when i do this, then it says that try again. I already changed my password and it still isnt working. Also all those keychain pop up messages keep appearing, for example "keychain login cannot be found to store (and then there is a number).

I am sorry for the long question but i really need help to fix my icloud. (i recently updated to os x el capitan)

Thank you:)