The problem with any jumpkick is just that, you're jumping.
You don't have a solid base, your centre of gravity is way off.
There's a reason why they call it a sacrifice kick (Sutemi Waza?) in Karate terms.
In Judo terms, you just helped your opponent do perform 1/2 of a throw. He doesn't need to think how to elevate you anymore he just got to figure out how to slam you as hard as possible to the ground.
For your info, I think it would be easier for you to find the kick if you googled 'butterfly kick'. Collin Chou uses it a lot in his movies.
I got two fists.. Don't make me use my head as well!