Should i get seconds if tests if i am still experiencing symptoms? normekg,stress,echo,holter.age28,no family hist,non smoker.move on to next cause?

Can't say no: I can't say don't get a second opinion since no test ( or doctor) is perfect. Chances are with all those tests normal, and with your young age, it's not heart disease.

Other things: perhaps get assessed for anxiety. you could start by doing the Zung SAS scale which you can find online. if it fits, then maybe talk with your pcp about a referral to a psychiatrist.