Your post is too rambling for me to address the main issues of your future. But, I can address one issue. Your sports doctor is NOT a concussion expert. He may be a concussion specialist but that does not make him an expert. Many suffer permanent disability from a concussion/TBI. The idea 'this only happens with people with preconcussion anxiety and depression is incorrect. The correct concept is that concussed people who suffered from anxiety and depression prior to their concussion have a much higher likelihood of prolonged symptoms. That does not mean that everybody who suffers prolonged PCS had an anxiety and depression condition that causes their PCS.

Do you have access to any other doctors besides these two?
The sports med doctor's ideas deserve a second opinion.

Where are you? Maybe some searching can find another doctor within your travel area.