lactose intolerant

I have found out I'm lactose intolerant about a year ago and stayed away from the obvious dairy and And lactose filled foods but for the first time I tried soy milk in my coffee because I had been drinking it black. And my symtoms were 10x worse than the lactose. I vomited and dirreah and even worse my throat swelled up!! Could my lactose intolerance be even worse than what I think