Help - My Jumping Position - Where am I going Wrong?

Debs Jumping Clinic... Can you give helpful suggestions on improvments? Slow motion footage, mostly from side. The bit Im unhappy about is the LANDING! I think it looks like i jerk back & bouncee, hit the bhorse back too hard. WHAT should I do to stop this?? Jump`phots to me look ok middle of jump.... but by landing am i left behind? or should i sit up quicker or stay forwar dmore... HELP HELP PLEASE THANKS EVERY-ONE FOR YOUR COMMENTS - I WILL BE TRYING THESE OUT