Well, there is a problem with Java nowadays, i have same problem, java keeps to freeze my pc like np.
So try avoiding having multiple java addons in same time, either choose youtube, or choose smth else, but try to keep it at addon only.
And it can help, i m doing it now, i used to have like 10 youtubes opened, cuz i have re-configurated buttons for browser (like to play-stop-skip) etc. And i got fatal error (was good cuz i was in lobby xD)
So now im just having 1 java plugin.
Those adobe updates are... >.<