Slow connection is slow

Recently my internet connection speed has been epically slow for reasons unknown. I have basic internet from Cox and it WAS decent, despite being around 56k levels (was able to log two computers on Maple and play Left 4 Dead). But now, it's so slow, it can take at least a minute to open a website. I have to reload Maple's website a few times because the page won't fully load. Logging into two computers is out of the question now since I'll lag so horribly, there's no point in training. I cannot stream any videos because it takes ages to load and will only play a few seconds before quitting. On my dad's computer, it takes about five minutes for Maple to start up... :v

I have no idea what's causing this lag but it's pretty hard to do anything on the internet now. I'll be lucky if this topic gets posted with no problems xD

But yah, cable modem speed slower than dial-up = sadfais :[


Any clues on what may cause this?