How to jump hurdles that are like, over half your height?

In gym we're in out track unit and we gotta jump hurdles and I SUCK because I'm so short and even when the hurdles are as low as possible they're still wayyy too high and I keep falling over on them. Any help?|||Im a freshmen in hs and i run the varsity 100m hurldes and i have been doing all kinds of hurldes since sixth grade, if you are really serious about running the hurldes you almost want to "attack" the hurdle by gettimng your steps down and jumping as low as you can over the hurlde and keeping your lead leg as straight as possible and following through with your trail leg tucked in and your knee level with yyour foot and out like a chicken wing then you hit the ground running once you make it over and try to get over low and fast, thats the best way that i can describe it, hope it helps :)