Youtube not working in Safari

Question

Hello, this is my first post.
Recently I have been experiencing a problem with running youtube videos in the Safari browser. It started to happen spontaneously about 1-2 weeks ago, and so far has not changed.
If I click a video to play (embedded like in faecbook or on another website or directly from the youtube page), the video tries to load but it never does. Usually, the page reloads (like if I had clicked the refresh button) a few times, then times-out. All other tabs currently opened in Safari are affected as well, just like I have clicked refresh on each tab. When I click on a tab to open it, it refreshes and I have to load each page separately.
The youtube video never loads at all, and usually i have to close the browser completely...
I thought this might have been a problem on the youtube page, but no one else is experiencing these problems...
I also tried to update Abode flash player, but this made no difference. My software on the mac are also up-to-date.
So far I havent found a solution to this problem so any help is appreciated. I think the problem is with Safari, so I was thinking to reinstall it, but so far have seen on these forums that this is not so easy to do.
Please help!

Answer 1

Please read this whole message before doing anything.
This procedure is a test, not a solution. Don’t be disappointed when you find that nothing has changed after you complete it.
Step 1
The purpose of this step is to determine whether the problem is localized to your user account.
Enable guest logins and log in as Guest. For instructions, launch the System Preferences application, select Help from the menu bar, and enter “Set up a guest account” (without the quotes) in the search box.
While logged in as Guest, you won’t have access to any of your personal files or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.
As Guest, launch the application(s) and test. Same problem(s)?
After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.
Step 2
The purpose of this step is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login.
Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards. Boot in safe mode and log in to the account with the problem. The instructions provided by Apple are as follows:
Be sure your Mac is shut down.
Press the power button.
Immediately after you hear the startup tone, hold the Shift key. The Shift key should be held as soon as possible after the startup tone, but not before the tone.
Release the Shift key when you see the gray Apple icon and the progress indicator (looks like a spinning gear).
Safe mode is much slower to boot and run than normal, and some things won’t work at all, including wireless networking on some Macs.
The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.
Test while in safe mode. Same problem(s)?
After testing, reboot as usual (i.e., not in safe mode.) Post the results of steps 1 and 2.