Having been to a few Catholic ceremonies... but with the p.o.v. of an 'outsider', Mass does have a heavy atmosphere, and it's hard not to be taken up into the emotional world that it creates. The incense, the litany - it's all there for an effect. And some people don't react well to the rising sense of tension that it all creates. Some people get a great sense of peace & release, it can be very healing and uplifting, while others are filled with dread and guilt... and some people can be triggered more drastically.

I wouldn't worry about it too much, Psyclox - you didn't physically harm anyone, but I probably wouldn't suggest going back to church anytime soon - or maybe choosing one w/a less 'charged' atmosphere, like a Universal Unitarian service.