That's exactly how falling is likely to feel. It's just instinct. I think, if I were going to go with a fall/jump, I might like to do it backwards. That way you don't anticipate the impact like you might as you watch it rushing towards you. I think ideally I'd like to do it from a plane. Ivm aware of the complexity of that, its just a best case scenario, 'what if' thing. Never going to happen.
Whilst some have survived failed parachutes it's pretty rare. Apparently though, if your body is limp as you hit the ground it does less damage than if you tense up. I doubt studies have been done but there are mathmatical and scientific reasons for the belief along with a few accounts that back it up however I don't think a few accounts really count as scientific evidence. Too many variables but as a working theory, fair enough.
I think those of us genuine in our unlimate intentions to ctb have thought about the act in detail. The questions around micro managing the event and method are testiment to that.