Welcome to HCM,
You have high blood pressure
,this reading 216/122 mm Hg, this is high enough to start anti hypertensive therapy.
It is good that you do not have any complication or cardiac involvement, your ECG and other investigation must be normal that is why you have been discharged.
If there is no significant abnormality,this is essential Hypertension
you should take care of your diet with salt
If you smoke please stop it,if you are overweight
please try to reduce weight.
Take regular exercise which help to reduce BP and stress
Please follow up with your Physician.
Please take care