I don't feel that video was that big a deal. The fencing on the sides, the open stock trailer and not representative of what the OP is dealing with. That is the ideal setup to train a horse to load.
To the OP I would never attempt to teach a horse to load without at least postioning the trailer against a solid barn wall. Back the trailer on a slight angle so the trailer is almost touching the solid wall and allowing no place for the horse to escape past the trailer. You are forming a sort of shute.
I then ask a handler to take the horse into the corner formed by the wall and the trailer and just guide the horse while I hussle the horse forward with buggy whips. They are used low down on the hind legs, not higher then the hock and are used to move the horse forward.
I have NEVER failed to load a horse within minutes, not even that most of the time.
Make escape past the trailer impossible, make the trailer the only safe place to be and you can not pull a horse into the trailer so the handler only guides the horse and does not apply pressure, that is the assistance jobs, to move the horse forward.
The other thing too is that so many people think "Oh my horse won't load" and go about it as it will be very hard, the horse won't load.
While I don't agree with thinking about auras and special colors, I DO agree with having a positive attitude. So many people set their horses up for failure by having a negative attitude about something. Be confidant, cheerful and very matter of fact. I do believe that horses can pick up on your energy and feelings, particularily if you are having a bad day, they respond to it.
Your post is full of desperation and anger- I would def try trailer loading when you are in a GOOD mood, because your horse will respond much better to you.
OP, I had similar problem. I tried to feed, lead ropes behind, dvds from known trainers, advices from Internet, and even had couple couple trainers out (both recommended to me), etc. Nothing helped. She was terrified. As a final resort I contacted one more trainer (who actually said he won't charge me a cent if he won't be able to load her). So... He made her work. Lunged back and forth next to the entrance of the trailer giving her a break only when she looked towards the entrance. Eventually she realized that the only quiet place is INSIDE the trailer and she got on. He made her in and out several times ever time asking her to stay inside the trailer, then asked me to do it.
Park the trailer in a corral or pasture where your horse stays so she can investigate on her own. The feeding is a good idea, too. Most of all, when you try to load her assume she will be perfect. Chances are she will tune into you and load more easily.
I must say I agree with draftrider. You do sound really upset and desperate in your posts, and if you go out with the intention of loading in the same mindset, you're setting yourself up for failure. (Thinking back, I'm pretty sure I'm guilty of the same thing when I was having trailering problems with my horse.) Even if you are confident and happy, your horse still may not load, but there's a LOT better chance that if you act like nothing is wrong and you expect her to load problem-free then she will.