Should i see a specialist for postural hypotension, or can my regular doctor take care of it?

Both: Some times neurologists that specialize in autonomic disorders or dysautonomia can help where your primary care doctor cannot, but usually your regular doctor can point you in the right direction. Treatments range from the simple (avoiding standing quickly) to prescription medications, and depend on your personal history.

PCP first is ok: There are many thing your pcp can do for orthostasis. Review of the medicines, re check your blood pressure. Suggest to wear elastic support stockings, get lab tests for cortisol level, renal function to rule out dehydration or low sodium etc.