SEARCH and SIGN IN

I have been having one separate database (all the same) that I can post that will not allow anyone to make any changes, AND one for only me to post and add and make changes.

All of a sudden, all of my databases would come up as SEARCH ONLY (including me) which is what I want. And off to the right would appear SIGN IN. I could sign in and I could make changes but others still could not.

Today, this all changed back to requiring me to have the two different databases to post. What happened ?

I want all databases to be SEARCH only for all viewers, and it necessary for me to sign in for only me to make changes, delete, add, delete, etc.

How can I get back to this method ?

Thanks