I feel your pain, literally! I did the very same thing on my first ride on my first road bike.

When I finally got up the nerve to get back on the back (several months later) I rode it in my yard, clipping, unclipping, stopping and starting. I also ot into the habit of unclipping only on the right. I have put about 600 miles on this bike since April and haven't fallen once.

Keep practicing!