> It is not possible to conclude from your description whether it is Sinus
or Paroxysmal Supra Ventricular Tachycardia
). There could be some clues in history - but a look at the ECG is must - especially the one during the episode.
> It is a vicious cycle - fast beats cause anxiety
/ anxiety causes fast beats
> Since you mention other situations - BOTH CAN BE FROM A COMMON CAUSE!? - like Thyroid (Hyperthyroidism
) / adrenal (Pheochromocytoma
> The first thing to do will be to document what you have - routine ECG
> The next step is / Ambulatory monitoring (Holter) / ECHOcardiography
/ Blood tests for thyroid and adrenal in addition to routine tests
> There are several more - in special circumstances - depending on the results of above
In general - it could simply be anxiety - relax - enjoy life - take things easy
See a Physician / cardiologist in the mean time - get examined, get investigated.
If the results are negative, be happy.
If they find something, nothing to worry - treatment can be properly planned and carried out
Wishing you a speedy recovery