I've had the same issues with anxiety on the bike (it's my first sport ever, I'm a big woman in my late 40's, and I had some nasty falls the first year.) I am blessed to have been taken under the wing of Master's World Champion racer & wonderful trainer. Why, I'm not sure, but it's turned my life around. Anyway, he did some road rides with me this spring and kept checking my heart rate - unreasonably high from the start. He sees me train indoors so he knows my fitness level in spin classes. His prescription:

We found a quiet, fairly flat 3 mile loop close to my house. My "homework" was to ride 3 circuits quite slowly, in very light gears. Something funny happened. I soon went into a state of relaxation. My breathing became very deep and even, my muscles relaxed, in fact, that state of relaxation continued for hours off the bike, too. When Chip phoned for a report on how it went, I described this weird sensation and asked, what was supposed to happen? "That."

Sometimes by trying too hard, we set ourselves back! It sounds like we're dealing with the same kinds of issues and goals. Pm me if you want to chat more.

ps, I joined an author's group a year or so ago. One of the authors? Susan Weaver! (it was months before I mentioned to her that I ride.) She's a very sweet person.