I can stop my feelings temporarily, but it's difficult to maintain for a long period of time. Yesterday my mom wanted me to get some meat from the local butcher, and inside there was just kind of a group of people, not really in any organized fashion. I took my place at what I figured to be the end of the line, and when I thought it was my turn, the guy called on the person waiting behind me... I didn't know how to react. Did I read the line wrong? Was I not following the signs? Did I annoy this guy? ...But then I managed to calm those nerves for a second, and I found myself thinking about myself in third-person more than first, seeing myself act as I should in the situation, not fretting about how I was doing that.
Anything I can find to calm me down is usually a charm, and this sort of third-person detaching mindset really works for me. I went home after the polite man behind me said I was ahead of him, popped the meatloaf in the oven, and ninety minutes later it was ready to eat, and I was satisfied. Even though I was scaring myself in the situation, I didn't let it linger in my head.