My best teaching tool was arms out to the side and eyes closed. It really tests your trust with your horse. I only ever jumped 2-2.5 ft at the most, but when learning to jump my trainer had us all (group lessons) go over everything from trotting poles to small 1/2-1ft jumps, with our reins on the neck and our hands out to our sides and sitting 2point.
Also I was taught to ignore the jump. Set your line and then look past the jump, once your inline for it let the horse take the lead and just feel him go for it.
I loved to jump, but it's been years for me. We used to also jump on our trail rides when I was taking lessons, over down trees and such. And like others have said you just have to trust your horse.. let him take you over, you just look past the jump. I remember being in my group class and us all on our horses watching each other jump over this huge tree that had fallen down in the normal path. I couldn't even tell you how high it was, all I know is we were all afraid of it, so it was bigger than our normal jumping height. And we just kept taking the jump, even with a few spills. Our trainer was definantly one for getting right back on and doing it again if you fell off.
I would get so frustrated with my self because I had a horse flat out refuse a jump due to my lack of trust and right over his head I went in to the jump, I was confusing him and he let me know! lol
It took alot for me to look past the jump, and that may be what will help you to get past your issues.
Can't wait to hear the post about how happy you are with your jumping, in the future. Good Luck!!