For those who wish to understand how the My Feed in the Top drop down menu works, here is an explanation:
My Alerts: Shows you only anime that you have subscribed to or new anime that has been added to the site. These alerts are alerts you have not read/visited yet.
New Updates: Shows you all the new anime being put up even if you are not subscribed.
My Friends: Shows you a list of your friends who are online.
Full History: Shows you all of your alerts even if you have them all read.
Mark Everything Read: Marks all alerts read which will make them disappear from the list.