Did this gentleman see a picture of what you eliminated or did he send you a link to a picture of the parasite he was referring to? I think that before reaching a conclusion based on someone's response to a brief description, it might be helpful to at least see a picture of the parasite he diagnosed.
I have eliminated something that I described also as sort of the size of a lima bean and sort of the texture of a mushroom. If you look on this site, you'll see a picture of the parasite this gentleman was telling you about:
I can tell you that the mushroom/limabean type thing that I eliminated looked nothing like the "fasciola hepatica" in the picture on this page.
And please know that I mean no disrespect to this gentleman who was probably trying to be helpful. I just think that when it comes to our own bodies we need to gather as much information as we can and make assessments for ourselves rather than relying on what someone writes in response to a brief description.