When you find the answer, share it! I too suffer from fear. This summer I had some great breakthroughs on my mtb. I think skiing (and taking ski lessons) all winter helped me learn to solve problems at higher speeds so I relaxed more. But racing cross is a whole 'nother world. I was thrilled to ride my cross bike on several miles of single track filled with tight corners and baby heads, but that's not the usual cross race terrain.

So, I have no answers, but I'm in complete empathy.