Suggest Treatment For High BP

I was to have some outpatient surgery and while they were getting me prepped........my blood pressure went out of control...........220/115......137 pulse..........of course they sent me home....Then my reg. doctor prescribed 25 mg. metoprolol (1 x day)...........I was already taking clonidine 0.2 mg. (1/2 tab x 2).......and hydrochlorothiazide 25 mg.................I am still having trouble with high blood pressure.........Should I be taking OTC potassium supplements??.......If so, how much?........Thanks so much:)