I agree your brake is crap. V-brakes are a must (at a minimum).
I was riding my homebuilt recumbent on a twisty road, going down a moderate hill at about 38 mph. A guy in a truck pulled up the intersection from a side road (I had no stop sign but he did). He looked right at me as I approached, and started to pull out before it registered in his brain how fast I was really going, then he came to a complete stop. I'm thinking there's gonna be a collision, so by force of habit I apply both brakes; the rear locked a little and started to swing out the rear end a little. I let off the rear brake and it straightened right out, but I continued to use the front brake to slow me more. Scared the bejesus out of me. I have v-brakes front and rear.
Moral of story- you need good brakes. If he
had pulled out I would have been able to avoid hitting him due to my brakes.