Why is my internet suddenly slow?

[Jordan]

So, my internet is suddenly slow. I can't find a particular reason for it. I'm not new to computers or anything, so the obvious answers should be out of question.
I am connected to my router wirelessly, but my connection is great. I'm getting about 52mbps, which should hardly be a problem. There are other computers connected to our router but they have never caused this problem before. Those computers also work fine. My computer seems to be the only one having problems. I have reset my router just to be sure, and I'm now positive that using wireless internet is not the problem.
I have checked for viruses and spyware, my computer looks clean. I have cleaned up my computer, uninstalling things I no longer need and junk. I haven't done anything new or memorable on the internet that could have caused this, just the typical stuff. Youtube, Facebook, etc. Speaking of Youtube, watching videos on it is next to impossible. They just buffer forever.
I play online video games like League of Legends and Starcraft, but they don't seem to be affected at all.
Also, it isn't a problem with my computers hardware.
I am currently running Windows XP.
I'm sure other people have had this problem before and I'm wondering if there is anyone that has been able to find and fix it. This has happened to me in the past, but I just ended up re-installing windows. I don't want to do that again because it would be a huge bother, seeing as my disk drive stopped working a couple months ago.
I hope I have provided enough information for someone to discern the problem.
An educated answer is preferred over the usual one sentence comments telling me my "internet just sucks"

Thanks
As a note, it has been slow for about 2 weeks. It never speeds up or gets any slower.
Seriously, I need the help. I have to get back to work on Wednesday.

[Dominic]

Well, it might just be your ISP is slow. Many people have today off due to the holiday so there will probably be a massive up swing in traffic. If it's especially bad you might see the congestion you're describing since all the sites you listed are already extremely popular.

Edit: Ah, that's a different story then. Definitely keep track of the date and times you experience the slow down and e-mail that information to your ISP so they can investigate.

- Dominic