I'm new here, too. With me it's more male authorities in the office - I get scared to talk to them, or I get super-friendly and agreeable, even when there's a problem.
One thing that's helped is when I tried to put the fear into words --
Is it "this guy's going to hurt me"?
Is it "This guy needs something from me, and that feels creepy"?
Is it "I feel like I'm a kid and what am I doing talking to all these grown-ups"?
Maybe there aren't any thoughts at all--it's just your body reacting.
Do you know what triggers the feeling? Something the customer says or does? Does it ever not happen?
BTW, I am totally ambivalent about therapy, too, and am going the do-it-myself route for a while, too.