Ditto to all of the above. The more you do it, the more comfortable you'll feel. I'm not just talking the pedals - if those don't work for you, don't feel pressured to use that. I'm actually thinking more about the riding in general - the more you get out and do it (on nice, quiet roads, and with DH understanding your fears), you will get more confident. Try riding the same route repeatedly, so you know the places where you are more nervous and need to 'have a plan' in mind, and the places where you can just focus on the riding. You'll be able to formulate solutions for the 'what-ifs' that run through your mind, and once you do that you'll get more comfortable. As you get more comfortable with the what-ifs on your 'regular route', then you can start branching out to riding other routes.

Don't worry that you are the only one with these fears. I just started riding this summer, in May, and I always ride with a heart rate monitor. While it has started getting better, I'd have high heart rate (like 105-110!) before getting on the bike, just because I was anxious. The general anxiety has decreased, but I completely understand the nerves. Again, the more I got out and did it (cycling is the only exercise I can get DH to do regularly, so I knew I HAD to go out, no matter how nervous I was feeling) the better I felt.

DH has been riding (on and off) for ever. And he didn't quite understand the fears, but he was generally patient with me. We started off riding the same basic loop, so I talked to him about places where I got nervous (there is a 3-way stop, for example, that I worried about), and he helped me formulate a plan for each of those spots. We also spent a lot of time in parking lots practicing specific situations, so I'd feel better. Talking through my fears with DH helped a lot, too, so that when we were on the road, he'd know where I'd be apprehensive and so he'd give me guidance/encouragement.

And (since I operate heavily on positive reinforcement ), I'd reward myself for 'baby steps'. Just sort of a mental pat on the back. Successfully stopping at an intersection. Confidently making a left turn. Taking a hand off the handle bars to signal a turn. Stuff like that. It might sound silly, but each little personal 'atta boy' let me know that I was making progress.

Frankly, I still have moments where I feel a little nervous, but definitely getting a lot of miles under my belt have made me feel a little more confident about handling 'unforseen' situations. Good luck to you, and keep us posted - hopefully you'll be out enjoying yourself soon!