The HomeHubs are s**t. End of.
It's not necessarily router or internet connection related, but I know tonnes of people who have had speed / reliability issues with the HomeHubs. You only have to do a quick Google search to find how many people have had problems.
First of all, give your router a reboot.
Uninstall all unnecessary add-ons from the computer. In fact, install all unnecessary software - it's good practice.
Try resetting your browser's settings back to default and check to see if there's any improvement.
Failing that, do you have any other computers in the house, and what's it like when you try to watch YouJizz on them instead?