Cold medication symptoms and conditions

I am a 43 year old woman in excellent health. One year ago, I was diagnosed with HBP and put on 12.5 mg of Toprol. I had a serious reaction to a cold medication that I took one month later and my blood pressure skyrocketed. My doctor doubled my Toprol. Immediately I felt extreme chest tightness, pressure, panic attacks, anxiety, depression and severe headaches. Until this time in my life, I had never even taken aspirin. I cut my dosage back to 12.5 mg. and now wonder if the extreme anxiety and feeling of impending doom is coming from this drug. I never had any problems before going on this beta blocker. Now I do not even know if I need it at all. How long do the side effects last if I stop taking this terrible drug. I have an appointment with a cardiologist in one week for some answers.