Thanks for posting and I'm sorry to hear you've been having some issues with browsing recently . I've had a look into this and can see that there's currently a fault ticket raised F003398969 for peak time contention. When checking the updates there is a review date scheduled for 03/05/2017 where we should have a further update on this ticket.
Are you connected wired or wireless? Is it only around peak times you're experiencing these slow speeds or throughout the day too?