Sinus tachycardia. Or anything serious?

Hello doc, 4 moth ago, i went to doc for chest pain and palpitation issue..I got xray and ecg done  ..xray report was normal and ecg was showing sinus tachycardia with hr 121 bpm. is this normal or anything serious? I'm also attaching the report..i also did thyroid profile test..my thyroid profile was normal..but blood test report shows very low vit d (4) and also low b12..so doc give me vit d tablets and some other calcium protein tablets and doesn't show any concern regarding my ecg report and said palpitation is mainly because of vit d deficiency and my anxiety( I have severe health anxiety)  after taking medicine, my palpitation and pain are gone..but i still have concern regarding my ecg report as I have severe health anxiety, I am scared of disease and after google I take a lot of stress even after doctor say it's all fine..so can you please tell me that my reports are normal?