Hi Geeks

Can you please help this non geek.  I was getting pop ups on facebook so I deleted some cookies - please don't ask what - I didn't really know at the time and it was a month ago but they seemed appropriate.  Since then (I'm guessing that was the reason) I haven't been able to sign in to anything on Chrome on my Moto G 3.  I'll enter my user name and password and it will just take me back to the blank sign in page for everything.  

Any ideas what I did and what I can do?

Thanks