Help! My ping has become worse.

I've always been one of the lucky blessed guys with a low ping (between 10 - 100) on wireless internet.
But the last 2 months my ping has "slightly" increased so now im playing between 100 - 450 Ping which is annoying me alot since i play Mesmer in GvG and need to be able to interrupt stuff

I recently installed a new Router 2 weeks ago in hope that it would fix some of the lag, but it "just" made my wireless more stable.
My Router is called:

D-Link Dir-655 and my wireless network USB card is also from D-Link called a DWA-140. To connect to my wireless i use a software that followed my D-Link router and netcard instead of the automatic Windows one.
My Connection Never drops but my ping is really not stable. I'm from Europe and the European servers Gives me between 63 - 300 ping and the american server Ping worse. My Pingdot never goes Red (Unless i just mapped to a place).

I've scannet my computer, no virus or spyware, (AvG Free 8.0, Ad-Aware, Spybot Search And Destroy) and i've defragged my Gw.dat which didn't even need a defrag.. My computer's recieved signal strength is between 80 and 90% so that shouldn't be a problem either. It's not possible for me to test Guild Wars without using wireless.
I'm using Windows XP SP 3 and my computer should be fine (Nothing great but is capable of running Guild Wars)

When i ping my router i get an average of 13 ms, i dont know what tracert is and i cant seem to ping the guild wars servers.

Right there is your answer. You're on wireless. There is no constant with wireless, so if you want better ping, run a CAT5 from your router to your computer's ethernet port.

This isn't him, I have always run on Cat6 at 100Mbps, full-duplex and where I used to ping between 10ms and 100ms, I now only drop as low as about 200ms. The sad thing is that I know beyond the shadow of a doubt that this is on ANet's end because my ISP just recently doubled my connection speed for free, and every other game I play, both FPS and MMO, has shown a drop in latency, including WoW. GW however, continues to go up.

The most likely cause of this is that their servers are becoming more stressed due to more players. More players in more instances means more power required. Oh and by instances, I mean the explorable world and missions, unlike most MMOs. If you have more players, you need more power, and while GW will probably never be as populated as WoW, it is growing and now the servers need to grow along with the player-base.

Oh and before you tell this IT tech with over twenty years of experience that more players doesn't increase latency, you can always perform a basic ping test to ANet's servers and see if you're being choked somewhere along the way or not. If you can ping 100ms or less to their servers, but the game is higher, it has to do with the client or server, and unless your system is sub-par for GW, your client should be in the clear.