Hi. I have the same exact disorder. About 10 years ago it was so bad and I had no idea what it was. Went to a psychologist and after talking to her about my lifestyle and what was going on, she explained to me that it was panic disorder. At that point, it was just great to get an answer about what the heck was happening to me.
The "butterflies" feeling was so horrible, it had been going on for about a year at that point, that I just couldn't take it anymore and felt suicidal. Fortunately, I went to the doctor. Ultimately she prescribed Zoloft and at that point she could have prescribed anything and I would have been glad to take it as long as it took away that feeling.
Anyway, after about 2 weeks ALL SYMPTOMS GONE! I was the happiest guy on earth to say the least. Eventually I weaned myself off of the Zoloft (took it for about 9 months) and no symptoms for 7 years.
Since then I have had to go back to the Zoloft (panic attacks) which is ultimately fine with me. I am still dealing with the "can't catch my breath thing" but found a possible cure for it that I will try. It is called the Buteyko Method and requires no drugs. Google it fro more info. Good luck to you and stay strong.