How to stop my photos and texts from showing up on someone else's iCloud?

Hi i recently logged into my brothers iCloud on my iPad few days ago and i logged out like 3 days after.

Then he told me that he started seeing my photos in his gallery and some of my iMessage texts. Please what can i do? I have already logged out of his iCloud and signed into mine but he can still see some of my photos in his gallery and some of my chats and i find this very annoying. Please what do i do?