Potassium deficiency is usually a transient thing. If there is something persistent there it is usually pretty serious and needs to be addressed pretty quickly. If you had ongoing problem with potassium deficiency you would most likely know about it by now! Sodium and potassium levels are part of the basic blood work, because they are a bit like oxygen... they are essential for life.
It is *extremely* unlikely that you have a problem with potassium deficiency. These are the major causes of it:

Potassium deficiency due to lack of potassium rich foods in the daily diet, i.e. insufficient potassium consumption.
Excess potassium excretion through bowel motion or urine.
Losing potassium as a result of vomiting, diarrhea or excessive sweating.
Use of medication which can interfere and bring down the potassium levels in the body.
Excessive use of diuretics and laxatives.
Health problems such as diabetic ketoacidosis or chronic kidney failure.
Hereditary defects of renal salt transporters, such as the Gitelman syndrome and the Bartter syndrome

Here is a comprehensive list of symptoms of anxiety:
Anxiety Symptoms, Signs, Treatment - anxietycentre.com