Unexplained Tachycardia - Help!

I am a 45 year old female. I have had SVT episodes my whole life, but over the last year they have become increasingly worse. I went in to a cardiologist and they dismissed my symptoms as they were not “life threatening”. After that, I was in the ER twice and was finally approved for an ablation. I had the first ablation in February. It was fairly extensive and they called it successful. Shortly after, I was back in the ER twice with more SVT episodes, however they were labeled atrial tachacardia. I felt horrible and my heart rate would rise to 140 or more just getting off the couch. On one of the ER trips, they put me on Flecanide and metoprolol and it was recommended to get a second ablation. These two medications relieved the symptoms to a tolerable level. I stopped taking it about 3 days before the next ablation in March per the Dr.s instructions. I went through the second procedure and they were unable to induce it and could not perform the ablation. They told me to go back on the meds and try a third one. I didn’t take any meds at all thinking maybe they were still in my system and that is why they couldn’t induce it the second time. They schedule the third one on May 2nd. Went through the whole thing again and they were still unable to induce it. My doctor is very frustrated and basically said he has no idea why this is happening. He called it possible POTS or Dysautonomia. He recommended Mayo for a consult. In the meantime back to Metoprolol. I am beyond frustrated and have no idea what to do. I also get severe migraines about once a week in addition to extreme fatigue all the time (I had this prior to my first ablation). I’m afraid to exercise at all because I get so winded and it is so uncomfortable to really do anything. I am so sick of hearing it is “not life threatening”. Maybe not but it is “life altering”. I was not like this prior to my first ablation, it was just the occasional episodes and few ER trips. Anyone have any thoughts or suggestions or similar experiences? Any help would be appreciated!