Hi Jenny, well again I must say well done on getting the odour down so much, I know it's frustrating that it isn't completely gone, but it's still a massive achievement, and hopefully the next regime will help you decrease that even further!
I noted though that you say "you smell yourself", which I know mightn't be the nicest thing but at least it means you know when you are smelling and you can maybe detect changes in how strong the smell is?
I know you're sceptical of the doctors after the parasite thing, as am I, but I'd definitely recommend going ahead with the GI test. The medical community has only recently caught on to how important the gut microbiome is to our health, with some papers showing how changes in it are linked to cancer and mental diseases. It's even gotten to the point where fecal transplants are being trialled as treatments to a host of chronic diseases! With that in mind, the GI test may be a good idea and it could be carried out by doctors who finally are getting a grip on what could be wrong with us.
Best of luck with it anyway Jenny, and keep us informed!