Tethering works on laptop, but my phone can't go online?

[se1ene]

For a couple of days I've been able to access the net on my laptop through tethering. And it works fast.
But when I try to go online on my phone it doesn't work! I'm not getting it!
How can my phone provide internet to my laptop, but the phone itself can't connect? Once in a while It might go online, but most of the time it says 'can't connect'.

I've Samsung galaxy note 2 and previously I've had no problem with this....

 

[SpookDroid]

Do you have trouble going online only when tethering your laptop or all the time?