I took adderall for 15 months 20 mg daily for recreation use. i stopped cold turkey and had extreme panic attacks. is this normal?

Yes, cessation rxn: Adderall is a dopamine/norepinephrine stimulant that results in increased arousal in the brain stem (reticular activating system, RAS). When you take adderall for several months, your system accomodates. When you stop abruptly, your RAS attempts to compensate and can produce far too much norepinephrine and dopamine, resulting in increased anxiety and possibly panic anxiety; See your PCP.