You may have a weak Internet signal. You can try turning off other devices in your house that use the Internet. That might help. Another thing would be to completely turn off your computer and restart it. That might also help with the loading time for videos. Best of luck to you.
try to put the quality at lowest setting (it's the little gear by the volume) or you could clear your all together internet history , YouTube history, and clear cookies hope you have speedy steaming :)