Lactose intolerance confusion?

So I have been dealing with really bad health issues, everyday I would feel sick to my stomach. I finally decided to cut out dairy and my symptoms left completely. Well last night I ate a good amount of this queso dip that's made with Velveeta cheese, which has a very high lactose content and I feel absolutely fine. But a few weeks ago I tried a little bit of sour cream and that made me sick...does anyone know what could be going on? Am I just lactose intolerant sometimes? I'm so confused!