Accounts accidentally merged?

[Jupiter15]

My dad was attempting to set up a family account with him, my sister and I. In the process I think that his Facebook account must have become connected to mine as now when I log into my account using my email and password, it brings me to an account with both of our playlists on, his name and his (Facebook) profile picture. When he logs in with his email and password, it brings him to the exact same account. We cannot listen to music at the same time. My sister's account is not affected. Also in the process of creating a family account, I seem to have become the owner of the family accounts rather than him.

How can we unmerge our accounts/make him head of the family account/take his Facebook off of my spotify account?