A little help, please? (I've tried everything D: )

For the past two weeks now I've tried to delete my internet history.

And I've clicked on the 'Clear Browsing History' thing and supposedly deleted my history 3 times now (and this is just today). It's not I've been on anything inappropriate or whatever, it's just that I clicked on something and I really didn't mean to, and if my dad sees it he'll go nuts.

You see, my history is deleted off of the 'History' tab-bit-thingy, but when I go to search for anything in the little Google search bar at the top of my page it comes up with all my recent history - Facebook and Mibba and Youtube... and the thing I didn't mean to click on.

So... how the hell do I delete this history? I've also tried clicking the little 'X' that comes up next to the search, but the search items come up no matter how many times I delete them.

Toodle pipski!
Unneeded intricacy