Can access the internet but cannot download anything, or watch videos.

Salutations!
recently i have come across a rather bizarre problem with regards to my downloading capabilities. i can connect to and access the internet, and browse web pages like normal, but when it comes to watching videos of almost any kind, or downloading, well, anything, my computer suddenly stops downloading/buffering and acts as though said download has been frozen in space and time. any information on what may be the problem would be greatly appreciated. also, please feel free to let me know what further information is required, as i am sure more will be needed to accurately figure out what fresh hell i've landed myself into.

i wish you all a pleasant day/night.