High heart rate, anxiety, shaky-sweaty hands

Not sure if this is the right section, but I can't find any closer ones so here goes..

I%u2019ve been having recurring episodes of what looked like to me hyperthyroidism symptoms after some research. I%u2019m a 23 year old male and these episodes started for me when I was 17. These episodes are infrequent, I say they occur on average once a year. Each of these episodes would last 1-2 weeks and go away without any medication or anything. These symptoms include pounding heart, higher heart rate than normal, high blood pressure (range: 136/86), hand sweat, shaky hands, slight headache (temples), anxiety, and moody. But I have not notice any increase fatigue or restlessness or bulging of my neck (if it%u2019s hyperthyroidism). My family and I do not have any history of any heart ailments or diseases. I am not on medication of any kind other than daily supplement pills - vitamin C and Omega3. The first time I%u2019ve had this (awhile ago) I went to the two doctors and both of them told me it%u2019s no big deal and say it%u2019s simply just stress and maybe hormones. Neither of them diagnosed or even mentioned to me the word %u201Cthyroid%u201D. They didn%u2019t perform any blood test or urine test on me. They send me back without any medication. Unsatisfied, I went back to them and performed two EKG tests, both of them showed my heart rate was faster than normal, but the doctor said my heart beats were fine and my heart is healthy. Convinced, I finally gave up and decide to let time heal it. After two weeks, the doctors were right, the symptoms went away all by itself. Then about a year or two later, the episode came back, so I just ignore it and live my life. Again the episode went away after a week or two. This cycle went on until now, which I am currently having the episode again. This is probably my 5th or 6th episode. Hopefully this episode will again go away like my past ones, but I%u2019m just wondering if I should be alarmed as these are signs for something serious, like a thyroid storm which I read about if hyperthyroidism goes untreated, if this is even what I have first of all? Or is this a sub-acute thyroiditis? Since I am currently not medically insured, I don%u2019t want to go to a doctor to have them sending me back home again like in the past. But is this a sign for something serious? I would like some professional opinion beforehand, thanks!