One reason why it took so long for my endometriosis diagnosis is because even though I had complained to my family doctor for a few years that I was taking far too much medication and that this couldn't possibly be normal, she didn't take me seriously. I finally insisted on some tests and eventually referred myself out. The next time I saw her, after my first surgery where severe endo was found, she said she never guessed it was that bad. I reminded her that I had told her several times that I was in severe pain and taking too much medication, her reply was "But you said it so calmly."
Someone told me that doctors are taught to observe body language. So if you're in control and not screaming in pain at that moment, too often you're not taken seriously. And like you, it's not my style to rant and rave in front of other people.
Sue Ann