Be fairly careful with a beta blocker. It is not really a wise choice for lowering steroid induced blood pressure issues. A beta blocker you can not just start and stop as needed like a Diuretic, Ace Inhibitor, ARBs, or Calcium Channel Blockers of the Dihydropyridine class. They also take to time work, they are not immediate and they also demonstrate a rebound effect if not discontinued properly. Which beta blocker do you have?
L-Theanine and Terminalia Arjuna are solid blood pressure control options as is celery seed extract. Potassium Nitrate tends to dilate more of the venous pathway whereas we are concerned with Arterial pressures but it can help.
Hopefully you don't have issues though