Try n relax consult with psychiatrist it can be ocd /anxiety spectrum first definite diagnosis to be done.
Duration of treatment depends on symptoms ,response to treatment and severity ,frequency,and relapse after treatment etc .min 6-9 month Max depend on case to case .
There are some side effects like every medication but do not much worry,concerned Dr will take care you don't worry .
Next Steps
consult with any psychiatrist/psychologist