What is going on?

Around a week ago I was smoking and began to feel an uneasy feeling in my chest. Anyway, a pressure began to fill my chest. My heart rate raised rapidly, and i was unable to regulate it with deep breathing( i have anxiety). I thought i may be having a heart attack so i rushed to the E.R. They performed several EKG and blood work and said my heart was healthy and that I did not suffer a heart attack. The EKG was abnormal but they said it wasnt to the point of being life threatening. The pain eased away but a slight pressure remained on my chest. That night I played basketball and I felt good. The next day I tried smoking again. After smoking I ate a piece of steak, and took some Pepto Bismol. This upset my whole stomach with gas, and now i felt a gurgling sensation in my abdomen along with stiffness. The pain which was once by the left side of my chest near the breast area was now closer to the center of my chest. I rushed back to the ER and they told me it might just be gas. They asked me a lot of questions and diagnosed me with gastritis. They prescribed me Prevacid but i was given the substitution Omeprazole. I have been on this medication three days now and the pressure remains and is now in my whole chest area. I have not smoked since my last visit to the E.R yet i still feel pressure. I have been dinking peppermint tea and eating very healthy. Last night I played basketball and when i left the gym my heart was beating fast and I was unable to yawn. The pressure was immense and did not subside until a hot cup of tea. Even when the pressure doesnt feel so bad it never completely goes away. Although the ER said my heart is healthy it is a scary feeling when the pressure comes on and my heart starts racing. Does anyone know what this may be? and if so how do i get rid of it?

[Fuzzz]

If it is gas, then maybe simethicone would help.  

An EKG is not the final test you need to check out your heart.  Call your primary care doctor and see if you can get an cardiac stress test.  They'll also probably do blood work.  It's not unusual to need further testing to be certain; a cardiac catheterization is an extremely useful test.  But some hospitals can ONLY do a cardiac cath and are not set up to do any intervention at the same time that your larger hospitals could.  

If your heart checks out, it could be GI.  When I had a gallbladder attack, I had a terrible squeezing sensation around my lower ribcage.  If I hadn't just found out I had gallstones, I would have wondered if it was a heart attack.