My pulse would go up to 160-180s so i was put on metropolol but now my blood pressure goes down to 88/48. what should i do?

A BP of 88/48: In the presence of dizziness, lightheadedness, nausea, & fatigue is concerning and rx adjustments may need to be made. That said, this BP may be within the normal range for a 16 year-old female. Many forms of asvt (supra-ventricular tachycardias) require selective beta-blocker control; the prescribing md should be notified of these values asap to advise you further. Good luck!