I feel like that all the time. You just have to keep going back, and find a new doctor when that doesn't work. Some NP/PAs are especially bad about taking you seriously. You can get stuck in a "holding pattern", when what you need is action. Sometimes seeing a different type of specialist helps; a neurosurgeon feather than orthopedic surgeon, or an Internist rather than a GP. Sometimes it's just the culture of the physician's office. I've heard taking someone with you to appointments helps.

Best wishes.