Watching the video helps a lot. Your horse appears to be honest and safe, and that's a real plus. I have a perspective to share that may help you.
I believe that are frustrating yourself by showing your horse before YOU are ready to do so. When I was studying acoustic piano towards a degree I was required to both give recitals and I was assigned randomly to accompany another instrumentalist every semester. My keyboard professor, from which I took a weekly lesson, encouraged our recital music to be pieces that we had already mastered. We would often work on next year's recital pieces early, so as to hammer out any difficulties and help the performance of such to be fluid.
This age-old practice seems to have been lost. So often people play pieces or perform in an athletic venue at a level not yet mastered. It isn't cheating to enter a class at a level below that which you are currently working on.
DH and I have been so wrapped up with our hobby over the last 26 years, for instance, that I've never shown my horses. I've trained over 30 horses in that time, and ridden multiple 1,000's of hours. If I decide to show in the future it would be as an adult novice competing against many adults who have never had my body of experience. Should I decide to do so in the future I will probably show a horse at a level below that which he has accomplished as well.
You seem so unsure of yourself in the show ring. Why don't you give it some time and try showing again in 2012 after you've had more practice? I think that you will enjoy it more than you are right now. =D