Your husband wouldn't happen to be politically conservative would he (I guess if he is you are too)? My family is and I suspect that's part of the reason why they don't believe me - too much respect for authority, as in the wisdom of the medical establishment. It really is quite fascinating how much people can stick to their beliefs in the face of conflicting evidence - my mom really gave the game away when she recently proclaimed 'I'm not interested in the truth'. Is this somethng you learnt about in your psychology studies? I was tempted to study that but was put off by its implicit assumption that most people are 'sane' or normal or well-adjusted - which is quite clearly an unfair assumption in a modern context..
I think in your blog you mentioned how your husband doesn't 'believe in parasites', which is perahps the crux of the problem, in that his 'understanding' of the issue is clearly not based on evidence. Essentially trying to convince him of your parasites might be equivalent to someone trying to use reason to get someone to abandon their religious beliefs. Perhaps if you find a way to appeal to your family on a different level - a more 'human' level - then you may have some more success. Of course this is coming from someone who isn't believed by anyone in his family - my pop did but he went and died on me (actually he was ostensibly very conservative so that perhaps blows my earlier theory). I don't have the same urgency to get their support that you have - in fact a part of me quite likes that they don't believe me so they are more compelled to atone when I get better - which is imminent btw, as I've currently got a cold , which has practically never happened in the past, (didn't miss a single day of school with illness for instance)and is quite exciting given the way that parasites suppress our immune response.