Talk to General Physician on Covid-19 Effects

Please post this anonymously on Marham. I was tested positive for covid-19 on April 27. It was a mild attack and I recovered at home. On May 20th, I received my 1st vaccine shot. I also walked for almost 4kms that day and since then I am having palpitations and shortness of breath. I don't have cough, weakness or any other symptoms, but I don't have that stamina that I used to have before getting sick. Sometimes I have heart pounding and breathing issue even when I am sitting or taking rest. I can’t even walk for 5 mins now. Also I have difficulty in breathing while wearing a mask. My chest x-ray is clear. The doctor gave me anti-inflammatory medicine(Naproxen) and inhaler to use. Its been 3 weeks and I can’t see any improvement in my condition. Also, if I take eggs or nuts, these issues become worse. Please guide me what could be the possible reason of this issue and how to cure it? Should I go for ECG any other test/scan that you recommend?