This is an interesting little op-ed that describes exactly the kinds of situations I often see my clients experiencing, and is an example of having a patient advocate can support you.
The number one most important thing when this starts happening is SPEAK UP. So many people allow the doctors and providers to bounce them around like this. Express your dissatisfaction, be insistent when you speak with your doctors. So many times in my clinical practice when I ask patients why they are having a specific test, they just tell me "because my doctor sent me".
Ask questions, be sure you understand the answers before your appointment is over.
Make sure your medical records are being shared with the other physicians you are being referred to.
This is your body, your life. Take control of your healthcare.