Don't listen to what people are saying under your video, like replying to it. That IS NOT a D-Spin. That is a misty 7, or a bio 7. Misty and Bio are both off axis spins thrown forward. Misty is when you go inverted. Bio you do not. D-spin is back and inverted. So is cork.
To learn cork, you can do progression on trampoling. Whichever way you spin, jump, initate your spin wiht your lead sholder, then drop it down and back. BUT, to start of learning it, just try and do a 360 drop to your back. But have it be really spinny. And do it by droping your lead sholder, or left shoudler if you spin left. Once you can do that, jump higher and you just have to get the idea and visualize it in your head, and basically committe and try and pull it through. It's all you man, learn it. Remember, think of it as like a back cork. Bio's are forward corked.