Okay. My school has the same situation. But fear not, for I have a way around it that very few people know about.

Type in the URL httpS://www.ultrareach.net. Don't forget the 's' in https. It is a Chinese site, but there is a url bar there. Type in what site you wanna go to, then click the button to the right. (Pressing enter won't work). It will be slower than usual, but usually it bypasses anything). And if your school blocks that, like mine did, go to https://www.wujie.net. Same site, different domain.

EDIT: It will give a Security popup, just say yes, the site is fine.