I feel fear of my health condition. Me.

I overthink a lot and having too much tension in my life about my career and family problems.. And I can't sleep during night whenever i close my eyes lots of things come in my mind about my health and i feel fear that i will get heart attack or i will die this fear make me difficult in sleeping..and whenever i take tensions my heartbeat get fast and my body get cold and I get panic and feel heavy in chest and difficulty near neck and i get fear if i will get heart attack or what..i consulted doctor and he did a ECG and checked my blood report he told me I'm ok and prescribed me Vitblast-15 and Clonofit plus and told me my bp was abit high 140/80 nowadays i always walk 6000steps and eat vegetables and eating less meat..i get tired after my work is done but I can't sleep i get fear.. I also stopped taking medicines nowadays what to do please help me..