Help required. And negative thoughts.

I had my first panic attack in mid of September, 2017. Thought I was dying went and got the ECG it was diagnosed as left heart enlargement and my heart rate was 116. Since then I was not at rest at all got 2D echo done and after that Ecg everything came normal. Met Cardiologist he checked everything was fine though my BP was little high he did not give me any medication saying it cud be coz of my anxiety. Had severe acid reflux problems too.. Consulted a Gastro who suggested to take medication for acid and anxit 0.25 daily night for 5 days. After 2 doses my acid reflux reduced and I feel normal except sometimes I get negative thoughts that something will happen to me or to my loved ones. I will have to stop anxit 0.25 in next days. But I'm wondering will I be normal again. Also I was always very strong only got into depression when my mom died in 2005. I request suggestions on what exactly is wrong with me. What should I do to keep myself away from Anxiety and negative thoughts.