Sync and upload speed OK but slow download/browsing speeds

[#1]

Syncing at the usual speed, but despite disconnected, reconnecting, rebooting and being plugged directly in, I am getting very poor speeds, but download only.
The data rates are normal, but I can't say I've paid much attention to the attenuation stats before.
6 - Uptime: 0 days 01:05:29
7 - Data rate: 1003/6942
8 - Maximum data rate: 1012/7152
9 - Noise margin: 6.1/2.8
10 - Line attenuation: 26.0/50.0
Over the last few days, the ping times and upload speeds have remained the same, but download is falling significantly, however, browsing "feels" significantly slower than the measured speed difference, if that makes sense.
Reminder: The sync speed is the same as it always is, and I have checked (and can see by the router stats) that nothing is hogging bandwidth (for example, Windows update, Amazon fire, tablet etc all excluded)

31/12/2015 10:36 GMT	X.X.X.X	2765 kb/s	838 kb/s	35 ms
30/12/2015 23:53 GMT	X.X.X.X	2934 kb/s	836 kb/s	34 ms	
29/12/2015 10:05 GMT	X.X.X.X	4044 kb/s	763 kb/s	34 ms	

I noticed that the BBC website was down for quite some time earlier too and that never happens -  is there some kind of general net weirdness or DOS going on?

[#2]

Your line has had a large number of errors over the last few days, which caused a few disconnections and the speed to reduce.
I've made a change to your line profile to combat the errors and this should take effect within a couple of hours, hopefully after this you'll see an improvement in your speeds again.
The BBC issue is completely unrelated to your service.

[#3]

Thanks! Significantly faster, now:

31/12/2015 14:27 GMT	X.X.X.X		5650 kb/s	794 kb/s	37 ms
31/12/2015 10:48 GMT	X.X.X.X		2862 kb/s	835 kb/s	31 ms

I just thought that if the BBC was suffering such a huge DOS attack to take one of the world's largest and most resilient websites offline, that the sheer volume of traffic would have been affecting some of the traffic carriers in the same country.
http://www.bbc.co.uk/news/technology-35204915