Youtube buffering speed all of a sudden slower?

Okay, so I've been watching alot of youtube lately and one day, all of a sudden, the buffering speed SUCKS. so now a 5 minute video takes 15 minutes or more to load. its happened before, but not for this long... my interenet connection is the same, and this is really pissing me off. To like the point of killing my grandmother. So any advice or sollutions would be great. do it for gramma!