Heart problem or any else? I need.

In last 2 years i had 5-7 times heart palpitation without any reason.. (this happened in my work from scenario, before that i never feel like that). During that time, i feel dizziness, feel like im sinking and get panicked. I feel fear that i am going to die. Till i visited more than 10-12 doctors including 4 cardiologist, i took 5 ecg, 2 echo, 2 tmt, 2 chest xray, thyroid, sugar test and all the rest wer normal. I can't live happily and always worry about my health and heart, whatever symptoms happened in my body i think it's only/maybe hearts problem.. so something could happen to me.. Sometimes during walking i feel like im floating and my body feels weightless.. Every test were normal but i am not convinced because my problem not solved.. i am living with heart fear.. How to overcome from this problem.. what type treatment i need...? Attached are my latest ecg taken in the span of 2 months. Note: i never feel any pain, unusual sweating and breathlessness