I Am Thinking I Have Pots Or Svt. I Did

I am thinking i have pots or svt. I did have an ekg and echo done and they were fine so my doctor decided to put me on a heart monitor for 48 hours. I am exhausted all the time, lightheaded, dizzy, and can del my heart racing like crazy. Even if my pulse isn't high my blood pressure will be because i can feel my heart pounding. just walking up a flight of stairs my heart rate can reach 140. then when i wake up in the morning its usually between 130-160. then just walking around doing everyday things its 130-140. what do you think is going on? any suggestions of comments?