If you are using a digital blood pressure machine, take it along with you to the doctor and see if it is close. Perhaps, the devices you are using are not well calibrated, I don't know.
I have not heard of benign hypertension, but there are some that suffer from white-coat hypertension (doctor's office) I don't think it would run that high though. I do believe you should address this problem. I don't know if you're seeing a specialist for your other conditions, but at least mention what you've posted here and see what response you get. You may need to see another doctor to treat your hbp.
I am sorry your depression is so bad, I'm sure that zaps alot of your strength. I would suggest you mention your concerns to the doctor and not wait for him to say something. You do not want to wait for symptoms, as they generally appear after damage has occurred. Whether or not the machines you've been using are accurate, addressing this will give you one less thing to worry about! I wish you well!