lol, cept for the coughing up blood part...
As a confidence booster, I did a backflip and landed it the first time I tried.  If you are scared, test the jump several times.  I did my speed check on the jump to know how fast I needed to go, then did a 3, then just did a straight air and mentally timed my airtime to think if it was big enough.  The next time, I just did it and REALLY committed.  I hucked it.  Just make sure you pop off the jump, not just rotate backwards.  Jump up as high as you can and throw your head backwards.  Once you can see the ground again, the hard part is over.  Then just pull your knees to your chest, in a sense.  It makes your feet come over the top and back under you for when you land.  You can also judge how fast you need to do this when you are upside down.  As long as you can get ski on the ground, you arent fucked.  You've rotated enough taht you will just fall over.
Definately practice them on a trampoline.  Not for timing, but instead to get a good feel of the rotation and what it feels like.  Keep in mind you are gonna have skis and boots on so it will be a little heavier.  They aren't that bad though, if the jump kicks you up, then you are almost a quarter of the rotation through takeoff.  JUST THROW YOUR HEAD BACK AND COMMIT!!! TUCK IN AND ROTATE AROUND!!! YOU CEN DO ET!!!
P.S.  My first jump was a box.  Dunno how long, but at my highest point I was only about 6 or 7 feet in the air.  Once you land it, it makes things a lot easier.
We'll have you dead pretty soon.