Sudden Slow Wifi (unable To Fix)

i run the internet through my wifi, the service is provided by the apartment complex to everyone. it is an incredibly strong signal for the whole building, and i am right beneath the source so i have always had just an amazing speed on my internet. the other day, while chatting on facebook of all places, something happened (what i do not know) and the firefox crashed. since that moment the internet has been chugging. and i mean chugging! it takes almost 2min just to load a page. (this is not consistent however some pages load faster) downloading speeds have all but stopped (i don't know how to check for just how fast they are going) i can't even load up Internet videos now its so slow.

i tried several fixes for the problem, but being a noob i think i screwed it up worse because its even slower than before. first i used uniblue registry cleaner and speed upper thing. they just screwed up my computer even worse and it was taking forever just to open a file folder let along load a webpage. i did a system restore to undue that damage. i tried resetting the autotuning. that did not work i even did an ipconfig/renew release thing. that almost did me in. i finally got the internet running again. still slow.