I would try using the front brake only. The rear brake supplies very little braking power and locks up very easily, which can lead to a loss of control. Try teaching yourself to use the front brake only. In a panic situation, your training takes over and if you trained to use the front only, you will be ok. It also helps to have the rear brake set very loose. I have my rear brake set so loose i have to squeeze the lever to the bar to get it to lock up.

The only exception to the front brake rule is in the slippery stuff. In the rain, gravel, sand, etc, then use the rear mainly. Use the front sparingly and the minute you feel it start to lock up, release it.