Don't give up.
Monitoring, I think is key. When the doctor comes in, he, at times, has already made up his mind on the diagnosis. This happened to me last week.
I had requested and received my test results from wearing the heart monitor before the appointment. This gave me the opportunity to research the findings. As soon as my cardiologist walked into the room, told me I had sinus tachycardia. I questioned a few of the readings given his diagnosis. We had a LONG discussion. At one point - I gently told him "You are not listening to me". I AGAIN described what happens with my tachycardia events. He changed his diagnosis to Atrial Tachycardia. I am scheduled for an ablation mid May. However, I am going for a second opinion for peace of mind.
What I did not know, due to only TWO leads on the monitor, Sinus Tachycardia and Atrial Tachycardia can look the same. The defining difference is the onset. If your heart rate increases gradually, it is Sinus tachycardia. Atrial Tachycardia is a sudden increase in heart rate and stops the same way, suddenly. My tachycardia is immediate from normal range up to 135 (or higher) BPM and then, ends the same way, immediately. Another way for me to explain it was, as if I had snapped my fingers and the lights turned on and then after a period of time snapped my fingers suddenly turned off the lights. The importance of knowing how it started and ended changed my diagnosis. "ALL" the information from both test results and the patience's experience, is the only way for a correct diagnosis.
You stated you have a goiter. I also have goiters 1 so large it has deviated my esophagus on the right side and 2 smaller ones on the left. All my test functions for my thyroid come back in normal range. I have wondered if the goiters could have anything to do with my tachycardia. I noticed when my head and neck is at certain angles or downward - I can have an episode of tachycardia. If you notice anything similar PLEASE let me know.
You are not alone in feeling discouraged. I have been there and some days, I STILL am. I know, the "unknown" of what is going on and "feeling so bad", that after a while. "it wears on you". But I have decided to keep trying to find the answer. Living and existing are not the same. I prefer to LIVE. With God's help, I hope to find the answers. And hopefully with the answers, the solution.
Ms. Olivia I WILL PRAY for YOU. I hope to hear from you again soon. God Bless.