Awoke with chest pain a week ago!

I had taken Effexor for about four years until last August, initially at 33.5mg, to 75mg, to 150mg and then back to 75mg. I quit cold turkey last August with next to no withdrawl (withdrawal) symptoms (lucky I guess). I was continuing to have gastric issues and was tired of experiencing an upset stomach.

About a week ago I awoke at around 11pm with some mild chest pain. Not crushing or tight, more like sharp cramping. I got worried that I was experiencing some symptoms of panic attack so I went to my cabinet and grabbed at 75mg Effexor tablet and took it. Three hours later I awoke with a very rapid heart beat, and intense ringing in my ears. I ignored and continued with a dose the next night. After having had the same symptoms I ceased my dose and went to the hospital. I had an ECG, X-ray and lung function test. All came back negative with the lung function test saying I had some slight asthma. They gave me Ketotifen and Montelukast for this.

Now a week after all this, I still have a strong pounding in my chest (infrequent), elevated heart beat (most of the time between 88-90), blood pressure checked was at 141/90, trouble breathing, very gassy (belching and passing gass), stomach upset and light headedness. I try taking some Ativan that my mom gave me 0.5mg to try and help relax but I'm not sure if it's helping and I don't want to start dosing on something my doctor hasn't approved.

What the hell is wrong with me?