4-5 Months Ago I Started Getting Rapid Heartbeat

I m 22, a yr ago I had an ekg everything was fine, I didn t experience abnormal heartbeat. 4-5 months ago I start getting rapid heartbeat, usually when I wake up from my sleep, I would feel it thumping I get weak. I was at my new doctors office, they gave me an ekg she said my heart was beating extremely fast (I was very relaxed). They checked my blood pressure 3 times, it was high changes dramatically within minutes.. She prescribed me metotrolol 25mg, but I notice that I was actually experiencing rapid heartbeat more often the thumping was stronger than before I started the medication, I really can almost hear it.. I m either just sitting around doing completely nothing it would suddenly just go for about 2minutes just slow down within minutes it would happen again.. I was on metotrolol for 3wks and I just stopped 2days ago because it felt like it made it worse. I will find another doctor to go to, but does anyone have an idea what is causing it? I m changing doctors because they re not really professional so I don t feel that I can trust them with my health. I am chinese my doc is american chinese, yet her staffs aren t so I got a phone one time where they asked me to go by to pick up my blood test THING , which she really meant blood test report, also I did not understand anything she had said. So just to be safe, I rather try a different doctor. I ve only seen her once so it should be fine. Thanks for the info!