Two Apple IDs on one iPad problem

I have an iPad and I looked up can you have two IDs on one iPad and it said sure you just switch, sign out and resign in, when I did this it asked me if I wanted to save in the iCloud my contacts, notes, and Reminders, and I said yes ..then logged in the new Apple ID, and now on my husbands phone (the second Apple ID I wanted to add to the iPad) has all my contacts mixed in with his iPhone 10X, I don’t have anything of his on my iPhone 12, but my picture is beside his name (Apple ID) and his pictures beside my name (Apple ID) .. So how do I undo this.?