No offense, but if you're allergic to nuts/peanuts then you probably shouldn't be working in a restaurant that uses or makes anything that contains nuts/peanuts. As for the tripping, if you have proof the customer did it on purpose you might be able to get your work to pay for any doctor bills as it was a work related accident caused by a customer.

OP here, shocked I actually came across this and had to create an account to comment. The restaurant I work at does not have anything on the menu that contains peanuts or peanut butter so I figured I was safe. My manager actually brought the peanut butter in herself for when she wanted a snack. I didn't think anything of my allergy because we don't have those items on our menu and since we all get a free meal per shift and even get to eat the mistakes I never thought that anyone would bring in there own food. Although in hindsight I now know it would have been a good idea to tell everyone about it. I won't make that mistake again.