I don't mind interacting over the phone, but in person - I'm shaking. My anxiety goes to overdrive and I get panicky.
This may seem corny or something you've tried before to no avail, but what about rehearsing, role playing, or simulating the experience to help habituate/expose yourself to that kind of social situation? I tend to use this strategy to a fault. A better strategy for me is just going to different social situations on a very regular basis even if I don't want to. That's part of the reason I'm going to a conference in December.
In the long-term, group therapy would seem to be one possible treatment for social phobia in addition to individual therapy and medications.