Weird Lag
This isn’t how the internet works. You can’t compare lag in gw2 to no lag in other games or YouTube. Anets servers are in Seattle. YouTube has servers all over and the other games you play most likely are not in Seattle. You can run a ping plotter test (free to download) and put ncsoft.com in the search. It should show you where the problem is. Feel free to post a picture of the results if you need help.