Fear of walking. Any test need for me.

Hi Doctors, Recently i had fear of walking.. i always thinking i will get heart attack during walking.. so i decided it's better avoid walking. Few days before i got dizziness and fatigue during walking.. therefore i thought it was a heart problem. So i decided to avoid walking.. I did ecg echo chest xray twice and tmt once.. all tests were normal.. blood tests also normal.. BP and LDL only little high (around 140). But still i fear to walk.. how can i overcome this. Basically i used to walk 2km mandatory till 2 years back.. after work from home scenario, walking habit completely gone. Pleasure advice what is my exact problem.. is any test need for me. Even all test were normal i can't believe the reports.