Physical exercise is good for PCS. The flow of endorphins is helpful to the brain. If you get so uncomfortable from the exertion, I would want to have your blood pressure checked while you exercise. Are the headaches blood pressure related? If so, that is a bad sign.

The extra blood flow to the brain is also good, but not if it is increasing pressure in the brain.

I exercise in a pool. I cannot swim for very long so I walk back and forth the length of the pool up to 40 times. I combine the walking with breast-stroke motions with my arms. I never get winded but still get a good work-out.

You could also just go for long walks or bike rides. Just keep you blood flow going, even if at a slow pace.

The PT sounds like a fees churning mechanism. Some doctors get a referral fee for the referral. Some own a piece of the PT clinic or even employ the PT directly. $$$$$$