Little Pilgrim --
Finish your psych degree.
Look at nursing colleges where nursing-as-a-second-degree is available (Univeristy of Minnesota is one such place).
Practice what you are already committed to and then, if nursing is for you, enter school to secure an MSN.
If you still love psychology by then, consider the role of the psych-mental health CNS (Clinical Nurse Specialist). It is a highly autonymous role in which this Advanced Practice Nurse collaborates with psychiatrists and psychologists to diagnose & treat patients with mental health issues. Medication management is often a significant part of this role.
Good luck in your practice pursuits!
--p