Alyssa, one more thing. Both the bowl and the beaters need to be spotlessly clean. If there is one hint of oil anywhere the whites will not beat properly. Nicole is correct about not using a plastic bowl. Plastic will even absorb oil to say nothing of the microscopic amounts that get into the surface when it’s scratched. When baking it is always best to use a metal or glass bowl for all of your mixing.
I know that soy can cause inflammation and if you are not using soy free eggs, that could be part of the cause. It may not be the actual egg but the soy that is the problem. just a thought. Here is an article that has some interesting info on soy. http://articles.mercola.com/sites/articles/archive/2012/07/29/soy-effects-on-women.aspx?e_cid=20120729_SNL_Art_1