Replying to Back flip attempting

So tomorrow I'm going to attempt back flips again. I can land them consistently on tramps and I want to try them on snow again. My first ever attempt was off of a smaller jump and I didn't fully commit and sprained my neck. I figure this time if I actually get fully focused and sac up I wont hurt myself again. The only smallest jump built is probably a 20 footer that kicks you pretty well so hopefully I don't pussy out again.