I have been diagnosed with a right bundle branch block of the heart. Can I reverse this?

Probably not. A right bundle branch block is either slowed or blocked conduction in one of the three fascicles ("wires") that connect the top chambers to the bottom chambers of the heart. Generally speaking, if the right bundle block has been there a while, it'll stay. Sometimes they come and go, but that's like an extension cord on the fritz and sparking. Good news: you'll be fine with just the left bundle.
Usually not. Bbb is due to slow conduction down the right bundle. It is usually asymptomatic and benign. Rarely, it is caused by other conditions such as cardiomyopathy, endocarditis, pulmonary hypertension, lyme disease. If one is otherwise healthy, there is nothing to worry about.