Facebook requesting password in 'internet accounts' continuously

Hi all

Hoping someone can help. This started today. I have not had any system updates, I have not changed anything and I have not downloaded anything, but now I am being asked to enter my Facebook password into internet accounts repeatedly. I enter it, and it is accepted, but then I am asked for it again, and again and again. It won't go away. I can choose close or continue. If I click close, the box comes up again literally 2 seconds later. If I choose continue, enter my password, and it is accepted, the box still comes up again 2 seconds later. This goes on and on and on. Can someone please help me? This is on my macbook.

Thanks all.