I am a 38 yo female. I have a brief history of high blood pressure. Usually the diastolic number is high. I was prescribed Bystolic 5mg last week. I started a dry cough and took a Tylenol Cold with phenylephrine around 5pm. I had no idea this would cause a problem. I had a horrible night... crazy fluctuations in heart rate and pulse among a myriad of other symptoms (feeling faint, confusion, flush of heat then cold, difficulty speaking/swallowing). Today, I am still experiencing the flush of heat and then cold, weakness, trembling and terrible headache. Some of the previous other symptoms (experienced last night) are very mild today. I took some regular Tylenol today for my headache which seemed to intensify the other symptoms. My question is this serious and how long will this last? Thank you in advance.