I have a really bad sugar headache and I can't get rid of it :(

You mean a sugar headache from eating too many sugary foods? It helps if you drink water, a few glasses maybe, until your head feels better.

I second the water drinking, too much sugar in one go means your body pulls water to help balance the sugar intake which can make you slightly/severely (depending) dehydrated. Don't gulp loads down in one go, just sip over an hour or so and you should hopefully feel better.