One thought about your Seroquel -- I don't know if it is an antidepressant but with my antidepressant (Bupropion/Wellbutrin), it made me anxious (which make my blood pressure go up) when I was prescribed 300 mg daily--no problems with anxiety/blood pressure at 200, 150, or 100 mg daily. So maybe you were just prescribed to high of a dosage. Just one possiblity. Getting your blood pressure down to a healthy level is important. Everyone is right about the need to tell the doctor that prescribed it to you.