crying at work......the ultimate in embarrassment

OK, second day at my new job, for some reason working the register makes me incredibly nervous and tense. I wasn't shaking all day like the day before, but the stress made me CRY. I do that when I just can't handle the stress of something But talk about embarrassing. I went to get a drink and someone asked me how I was doing, and I just couldn't hold back or stop the tears. I had to go in restroom and then my trainer came in and said I was doing fine and didn't make any mistakes, but I couldn't stop the tears from trickling down. Finally I went back and bussed tables and got refills and cleaned up and everything was fine. I hope I can get through next week, I have to work for 6 days in a row and I don't want to have a nervous breakdown. I just feel so foolish!