Brief Answer:
You should see an internist.
Detailed Answer:
Hello,
Thank you for using HCM. I understand your concern. Your age is too young and your blood pressure levels are to high , to have an essential (primary) hypertension.
You should be screened for all the secondary possible causes of hypertension such as renal stenosis , renal parenchymal disease , Cushing syndrome , Pheocromocitoma, 
Hyperaldosteronism, 
Hyperthyroidism, 
Sleep apnea, 
Acromegaly, Coartation of aorta.
For excluding each of them , you need to do a series of laboratory and imaging exams .
The internist is the adequate doctor which may lead you in detecting the causing factor of your hypertension.
I seems a little bit long way to do , but i encourage you to go under it , cause treating the causing factor once is better than treating hypertension for all of your life.
There are even cases in which eventhough you do all tests for secondary causes , it doesn't get out nothing. At this case we are in front of an 
idiopathic hypertension , which we have to deal with. 
Hope this is helpful.
Let me know if you need more clarifications. Otherwise please close and rate the answer.
Kind Regards, 
Dr. Juarda