How can I get over my fear of bridges?

Ever since I got a car a few years ago, I have been very afraid to cross over bridges. Not all bridges,just big ones like in the San Francisco Bay Area. I feel bad because there are many friends and family I have there and this fear has paralyzed me in a way and as a result, I get to see these people less and less and it's not fair to them. What can I do to overcome my fear of bridges?