That really sucks.
I was misdiagnosed for years simply because my Doctor didn't want to carry out any tests, we'd get to the end of every consultation and he'd ask me if there was anything else and I'd say, "I'll need a Dr. Cert. for today" and he'd get this look like "I knew you weren't really sick, and you were just here for a sickie!"
It was so frustrating because I was so sick, and couldn't even drink water without vomiting, and all he'd say to me was "Drink plenty of water, and get lots of exercise."
I understand that there are a heap of people out there who do make it difficult for the rest of us, but if they'd just listen to what we're saying it wouldn't take long for them to realise that there is actually something wrong...
On the other side, I know nurses are extremely busy but I hate it when it seems like they're just ignoring people who are asking for their help!