Why does Britain bother with the USA ?

I mean, lets face it all that 'special relationship' stuff is a load of guff. The yanks don't actually like us that much. During WW2 we had lease lend from them where they flogged a lot of duff stuff at inflated prices. After the war we were crippled by debt to the US while they rebuilt Germany and Japan. These days they just use their alliance with us to try and add legitimacy to their dubious wars. And now with the defence cuts Hilary Clinton suddenly takes it upon herself to intervene in British domestic policy. What the problem Hilary, concerned we might not buy that overpriced Trident update ? All this after Obama has quite openly treated Britain with contempt, considering how much our politicians have fawned to the US. Why don't we just loosen those transatlantic ties and think more in the British interest ? America is no longer top dog, it is a busted flush, just like us.