I'm a bit embarrassed to say that this is the first time I've ever called the office of one of my elected officials. Not sure why I was always intimidated before, but now that I've gotten over my "first time jitters", it won't be my last... ;-)
You should never be intimidated to speak to these people. They are just, nominally, human beings. They work for you. They are probably scum. Never be awed, impressed, intimidated, or otherwise reverent because of some title such as “Congressman” or “Senator” or “President”